Improvements in or connected with Anodes for the Electrolytic Decomposition or Formation of Chemical Compounds.
Year: 1892

page_text: Date of Application, 17th May, 1892-Accepted, 18th June, 1892
COMPLETE SPECIFICATION.
Improvements in or connected with Anodes for the Electrolytic
Decomposition or Formation of Chemical Compounds.
I, ALFRED HENNETON, Electrical Engineer, of 152, Rue Solferino, in the City
of Lille, France, do hereby declare the nature of this invention and in what
manner the same is to be performed; to be particularly described in and by the
following statement :-
The present invention relates to the anodes or positive electrodes of apparatus
for the electrolytic decomposition or formation of chemical compounds, and has for
its principal object, to diminish the electrical resistance of the said electrodes,
without reducing their durability.
For this purpose, I compose the anode of the following parts;
1. A framework of copper or other suitable conductor of electricity, adapted to
distribute the current uniformly to all parts of the electrode and to give it the
desired rigidity;
2. One or more conductors fixed to the said frame or made in one piece with the
same and connecting it with the source of electricity.
3. The metal which is directly active in the electrolytic process and which may
be made of platinum or any other suitable metal or alloy incorrodible by. the
electrolyte for which the electrode is constructed. This active metal may have the
shape of thin rods, wire or wire netting, sheet metal, either plain or corrugated or
perforated; it is well soldered or brazed to the circumference and the cross bars or
intermediate bars of the metallic framework, so that each panel of the latter
constitutes a small frame to which current is supplied by all the adjoining sides or
crossbars.
4. An insulating material which covers the metallic frame mentioned above
(No. 1), so as to prevent its contact with the electrolyte, while allowing free access
to the immediately active parts of the electrode (No. 3).
The insulating material should be incorrodible by the electrolyte, and cover the
frame, as well as a portion of the conductor (No. 2) in such a manner, as to form
with the same one rigid piece and completely exclude the electrolyte, thus rendering
the electrode quite incorrodible or unattachable by the electrolyte employed.
The accompanying drawings show an electrode embodying my invention and
indicate a method of making the same.
Fig. 1 shows the metallic frame, together with a conductor A which supplies
current to the same.
Fig. 2 shows the framework, after it has been provided with the directly active
material in the shape of wires (extending across the panels).
Figs. 3 and 4 indicate a method of covering the frame with insulating material.
Fig. 5 shows a finished electrode.
The insulating material mentioned above may be ebonite, gutta percha, celluloid,
cellulose, porcelain, glass or any other suitable material, applied to the frame by
casting, moulding, compression, baking or any other suitable process or combination
of processes.
In the case of ebonite, the desired result may be obtained by moulding, pressure
and heat in the following manner;
In a metallic mould made of two parts, Fig. 3, the cavities of which are adapted
to receive the ebonite (or which correspond in size and shape to the ebonite parts)
I place on each side or half a sheet of indiarubber ready for vulcanizing and cut to
such a shape, that it will fit exactly into the cavity of the mould.
I then place
upon one of the said indiarubber sheets the frame Fig. 2 provided with its
incorrodible metal or alloy and with its conductor, as indicated in Fig. 4 by dotted
LD

page_text: lines; subsequently I place the second part or half of the mould (containing a sheet
of indiarubber as described) upon the first, bolt the two parts together, apply
pressure and bake them, so as to vulcanize the indiarubber, and convert it into
ebonite. Finally, I allow the mould to cool and remove the anode, which is now
ready for use.
Owing to this improved construction, the frame Fig. 1 may be made of copper,
brass or other good conductor, while the incorrodible material, which has a high
electrical resistance, is completely utilized as an electrode and not as a mere
conductor, or distributor of current, the latter function being performed by the
copper frame.
It follows, that with a given weight of platinum, my improved electrode requires
considerably less electro-motive force than an ordinary electrode which has no
frame. For example, if of two electrodes having the same dimensions and receiving
a current of 30 amperes each, one (represented by Fig. 6) has its incorrodible
metal fixed to the conductor at the upper edge only, while in the other the same
metal is mounted on a frame (as indicated by Fig. 7), the current will be distributed
as follows;
In Fig. 6 the whole of the current distributed by the third or lowest row of
panels must first pass through the first and the second row, while that distributed
by the second row of panels must traverse the first row.
If the distribution in this electrode is uniform, the first row of panels carries
therefore 30 amperes, the second row 20, and the third row 10 amperes.
In Fig. 7, the number or surface of inattackable metal wire is the same, as in
Fig. 6, but each row of panels receives only 10 amperes, and the electro-motive
force necessary for overcoming the internal resistance of the electrode is reduced
accordingly. Consequently, my system of electrodes is a means of reducing either
the electromotive force or the quantity of incorrodible metal necessary for the
electrodes.
The quantity of incorrodible metal may be further reduced by arranging it in
panels in the manner indicated by Fig. 2.
The shape of the whole electrode and of the frame, and the manner of dividing
the latter may be varied to suit different requirements, the drawing being merely
given as an example. The conductor or conductors may also be connected with the
frame at various points, and the shape and sectional area of the incorrodible metal
(such as wire, woven fabric or sheet metal) will depend on the work which the
apparatus has to perform.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. An anode or positive electrode having a metallic frame, to which is fixed the
incorrodible or inattackable material in the shape of wires, woven fabric or sheet
metal, substantially as described.
2. An anode or positive electrode containing a metallic conducting and
distributing frame, to which is fixed the incorrodible or directly active material and
which is covered and protected by an insulating material applied by moulding,
casting, pressure, heat or any other suitable process or processes, substantially as
described.
Dated this 17th day of May 1892.
HUELSER & Co.,
Agents for Applicant.