Improvements in Apparatus for Electrolytic Decomposition.
Year: 1891

page_text: Date of Application, 31st Mar., 1891-Accepted, 16th May, 1891
COMPLETE SPECIFICATION.
Improvements in Apparatus for Electrolytic Decomposition.
I, CHARLES KELLNER, of IX 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:-
Apparatus for the electrolytic decomposition of salt solutions or other solutions
or liquids, according to this invention, comprises a number of single cells for the
electrodes, each cell being formed by a frame covered with a suitable diaphragm.
The space enclosed by the frames communicates at the lower part with the supply
of the liquid to be decomposed, whilst at the top it is connected with the outlets for
the ions by perforations formed alternately on the left and the right in the
successive frames. The electrodes suspended in these frame-cells are connected
alternately, that is to say, those of the even-numbered (that is to say the second,
fourth, sixth and so on) cells with one pole of a current generator, and those of the
odd-numbered cells (the first, third, fifth and so on) with the other pole. The
electrolyte-for example a solution of common salt-being admitted from the supply
inlet simultaneously into all the internal spaces of the frames, having filled the
cells, and the current being turned on, the solution will undergo the well-known
decomposition, and as long as the supply is maintained, chlorine is given off at the
anodes, and is partially dissolved in the water, so that from the outlet channel,
which communicates with the anode frames, chlorinated liquid flows off, and
chlorine gas escapes; whereas sodium is liberated at the cathodes, and at the
moment of liberation, decomposes the water and forms sodium hydroxide, or forms
a solution of the same, so that caustic soda lye flows off from the outlet channel that
communicates with the cathode frames.
By changing the direction of the current, the anodes become cathodes and vice-
versa, so that then the solutions of the separated constituents each flow out of the
other channel.
In small apparatus of this kind, the outlet channels consist by preference of
lateral upper perforations of the frames, which when the frames have been
connected with intermediately arranged diaphragms after the manner of filter-
presses, constitute two continuous outlet pipes for the ions, which communicate
alternately with the internal spaces of every second frame, but in the construction
of larger electrolytic decomposing apparatus I prefer to perforate the successive
frames alternately on the right and on the left, right through laterally, and to
establish in this manner the alternate communication with the outlet channels which
are formed by the outer sides of the frames and a vessel enclosing the entire
arrangement.
The accompanying drawings illustrate the two constructions in their simplest
arrangements.
Figs. 1 to 5 illustrate the construction after the manner of a filtering press of
apparatus for ordinary cases, whilst Figs. 6 and 7 shew an apparatus for the
decomposition of large quantities.
Fig. 1 is a plan partly in horizontal section;
Fig. 2 a front elevation partly in longitudinal section ;
Fig. 3 is a transverse section, of one form of my improved apparatus.
Figs. 4 and 5, shew details of the frames, and arrangement of the electrodes in
section and plan.
Fig. 6, is a longitudinal section, partly in elevation, and
Fig. 7 is a transverse section, of the apparatus 1 prefer to employ for working
large quantities.

page_text: .
The frames R which constitute the several cells, are made of suitable non-
conducting substance capable of resisting the action of the solutions which are
introduced, and also of the solutions which are formed. In the arrangement shewn
in Figs. 1 to 3, they are provided at their underside R2 with an opening r of
suitable size, serving for the supply of the liquid, which communicates by a slot r¹
with the frame-space which is sufficiently wide for the circulation of the liquid. At
the upper side R¹, each frame is pierced by two lateral openings, which
serve for carrying off the ions. In alternate frames the left hand and right
hand apertures 23 are in communication alternately with the frame space, on
the one hand by the lateral perforations o', 0³, 05.
, and on the other
hand by the perforations o², 0, 08 so that, when the frames have been
suspended by the lugs on the rods F, and have been pressed by means of the
pressure screw F against the front plate F, the openings form a supply channel
common to all the frames, and the openings and each form an outlet channel,
of which for instance communicates only with the even-numbered frames, and ³
only with the odd-numbered frames. The space between the frames is divided by
diaphragms D of chemical-resisting material which increases the electrical tension
to the least possible extent. These diaphragms may consist of nitro-cellulose,
preferably of hexa-nitro-cellulose; they also serve as a packing for the joints, and
may be as shown in section, Fig. 3 suitably connected with rods d at two opposite
edges, for the purpose of greater convenience in handling.
•
,
The electrodes E are suspended with tight joints in a plate E2 which is designed
to be inserted at the top in the frames, and which consists of non-conducting
material from which the upper ends of the electrodes project for the purpose of
connection with the current conductors L L'. For the purpose of allowing of the
passage of the electrodes the upper wall of the frame is furnished with a corre-
sponding opening care being taken to ensure the greatest possible exactness of fit.
In the present instance it is assumed by way of example that both electrodes are
composed of carbon rods which are brought into conductive connection with each
other and between which are suitable spaces for the circulation of liquid; the upper
wall R¹ of the frame is therefore also provided with a corresponding number of
holes. In order to render the carbon rods capable of being readily changed singly,
their mutual electrical connection is effected in such a manner that the projecting
upper ends of the rods are recessed, and in these recesses connecting pieces e are
secured by readily fusible metal or alloy e' cast into the said recesses.
The connection of the electrodes inserted in the frames with the respective
current conductors L or L', is effected in each case by means of a wire l', in such a
manner that the latter is at one end cast in the respective outermost carbon rod,
and at the other end is immersed in a recess in the conductor, filled with mercury l.
It is obvious that the electrodes of one sign or the electrodes of both signs, may be
formed as plates, and that they may be made of other suitable material other than
carbon.
Electrolytic apparatus arranged as described permits of easy handling, ready
increase or decrease of the number of cell pairs, capability of readily changing
damaged parts, and of being easily cleaned.
For electrolytic decomposition on a very large scale it is preferable to employ
the modified arrangement illustrated in Figs. 6 and 7. For the purpose of making
tighter joints of a large number of frame cells, the whole apparatus is arranged in
a box-like vessel K whose cover consists of a number of parts k², k² k³ held in
position by means of suitable bridge pieces B and screws B¹ in order that any
required changes of single frames may be readily effected. The form of the
separate frames is in so far modified that the perforations r for the inlet of the
electrolyte, and and for the exit of the separated ions, are dispensed with,
and the frames have now only the lower slots, whilst instead of the lateral
channels o¹, o³,
and o², 0, 0
lateral openings t¹, t³, t
., and t²,
pass alternately right and left through the side portions of frames R.
In this case the frames, which extend with their sides up to the cover of the box,
t¹, to
05
...

page_text: are arranged with the intermediate diaphragms in the box-vessel K, and pressed
firmly together by means of the wedge m. Through a pipe R the electrolyte
passes into a recess in the bottom K₁ of the vessel, and rises through the slots rl
up in the frame cells; in order to be decomposed.
In consequence of the alternate succession of right and left perforated frames R,
one ion passes through the openings t¹, t³, t, into the side channel H which is
formed by the longitudinal wall of the box vessel K and the outer sides of the
frames R, on the left, and then flows off through the pipe R¹; whilst the other ion
into the channel H2 situated on the other
passes through the openings t2, 11, to..
..
side of the box K, and flows off through the pipe R².
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 apparatus for the electrolytical decomposition of solutions, or liquids, in
which the electrodes are suspended in frames and separated by diaphragms, so as
to form batteries, each of which frames is provided with two openings through one
of which the electrolyte to be decomposed passes into the frame-cell the second
opening in one frame being arranged on one side of the apparatus and the second
opening of the next frame being on the other side, and so on alternately thereby
causing one of the separated ions to pass out on one side of the apparatus, and the
second ion to pass out on the other side substantially as hereinbefore described and
for the purposes specified.
2. In apparatus of the kind specified in Claim 1, the construction of electrodes
of a number of separate rods E provided with bent pieces or with the wires l',
secured in recessed ends of the rods by means of readily fusible metal or alloy
substantially as and for the purposes set forth.
3. In apparatus of the kind specified in Claim 1, the use of diaphragms of nitro-
cellulose substantially as set forth.
4. The herein before described improvements in apparatus for electrolytic decom-
position constructed substantially as set forth with reference to the accompanying
drawings and for the purposes specified.
Dated this 31st day of March 1891.
מרזוז -
CHARLES KELLNER,
By L. W., per F. B.