Improvements relating to the Construction of Electrodes for Electrolytic Purposes.
Year: 1892

page_text: Date of Application, 5th Nov., 1892
Complete Specification Left, 5th Aug., 1893-Accepted, 9th Sept., 1893
PROVISIONAL SPECIFICATION.
Improvements relating to the Construction of Electrodes for
Electrolytic Purposes.
I, JAMES CHARLES RICHARDSON of 23 Claremont Square, Clerkenwell in the
County of Middlesex, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:
The object of the present invention is to provide for the employment of gas
retort carbon in a practical manner as electrodes for electrolytic purposes,
particularly for the purpose of electrolysing solutions of common salt.
Gas retort carbon direct from the retort is preferable to prepared carbon,
inasmuch as the preparation of the carbon increases its impurities, and renders it
more liable to disintegration, under the influence of the electric current and the
products of the electrolysis.
The retort carbon, however, as it is generally procurable, is very irregular in
size and form, and there is great difficulty in connecting the pieces together to form
a proper electrode, which will have both electrical conductivity and mechanical
cohesion.
According to my invention, I take the pieces of carbon as they come from the
retort, and drill or pierce them with holes or sockets, wherein I place a rod or
rods, so as to secure a number of pieces together to form an electrode. The
adjacent surfaces of the carbon pieces may be smoothed, or shaped so as to fit
together as far as possible, and cement or similar filling-in material may be inserted
between the pieces of carbon.
In this manner, the rod or core, which may be of metal, may be entirely covered
by the carbon and filling material, & thereby protected from the destructive
influences of the products of the electrolysis, even when totally immersed in the
electrolyte. At the same time, the bar forms a good electrical conductor between
the pieces of carbon, and a rigid mechanical attachment for the same.
Where the total immersion of the connecting bar or rod is not contemplated, for
instance, when the latter is situated near the edges of the carbon, the protection
of the connecting rod is not so essential; it may therefore be left uncovered.
When lead is used for the connecting bar, it may be applied by casting in the
following manner :—
Across one edge of the pieces of carbon, I cut, by means of a narrow emery
wheel or saw, a pair of grooves a short distance apart, leaving between them an
upstanding tang or dovetail.
A number of pieces of carbon thus cut, sufficient to form an electrode, are
arranged side by side, with the grooves in line, and are then embedded in sand, so
as to be quite covered thereby, with the exception of the tangs and grooves upon
the edges of the carbon, which are left uncovered. The uncovered tangs and
grooves stand in a trough formed in the sand, and running the whole length. This
trough forms a mould into which is poured molten lead, or an alloy of lead, as
lead and antimony. The lead sets within the grooves and around the upstanding
tangs, and forms a solid bar, connecting firmly together all the pieces of carbon.
A means of connection, electrical and mechanical, is thus provided, by which the
electrode can be suspended in the electrolytic tank, with but little expense for
cutting and manipulating the hard substance of the carbon. Bolts or lugs may be
cast with the leaden bar, if desired, in positions to facilitate suspension.
Dated this 5th day of November 1892.
NEWTON & SON,
Agents for the Applicant

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Construction of Electrodes for
Electrolytic Purposes.
I JAMES CHARLES RICHARDSON, of 23 Claremont Square, Clerkenwell,
London, Electrical Engineer, 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 object of this invention is to provide for the employment of gas retort
carbon in a practical manner as electrodes for electrolytic purposes, particularly
for the purpose of electrolysing solutions of common salt.
In electrical decomposition of solutions with insoluble anodes, carbon is usually
employed as the positive electrode, which material, however, is subject to disinte-
This
gration, and must be frequently replaced, at a not inconsiderable expense.
disintegration of the carbon cannot be altogether avoided, but it is found that
carbon direct from the gas retorts is liable to disintegrate, under the influence of
the electric current and the products of decomposition, less quickly than specially
manufactured carbon, than which, moreover, it is much cheaper. Gas retort
carbon, however, can only be obtained in rough pieces of irregular shape and size,
so that it is difficult, without considerable labour, to adapt it for use for electrolytic
purposes.
Attempts have been made to construct a carbon anode by embedding the ends of
broken pieces of carbon in lead or similar material, but this method is not satis-
factory, because a large quantity of metal is required to embrace the carbon, and
also because the metal, if applied by casting, is likely to shrink away from the
carbon, and allow it to become loose, thereby destroying, partially or entirely, the
electrical connection between the carbon and its holder.
According to my invention, I employ a metallic attachment for the carbon
fragments which are to form an electrode, but the attachment is such, that the pieces
of carbon cannot escape therefrom, while at the same time elaborate and expensive
manipulation is avoided.
In carrying out my invention, I select from a heap of broken gas retort carbon,
fragments as much as possible of a size, sometimes trimming them roughly by
breaking the edges with a hammer.
Having selected a number of pieces sufficient to form an electrode, I notch or
pierce them to receive a metal attachment, which may be applied in the manner
illustrated in the accompanying drawing.
Fig. 1 shews in side view part of an anode constructed according to my
invention.
Fig. 2 is an end view thereof, partly in section.
Fig. 3 is an end view, partly in section, of a modified form of attachment for the
carbon fragments.
Fig. 4 is an elevation of the form of attachment shewn in Fig. 3, applied to a
large piece of retort carbon.
The attachment for the carbon fragments is applied by casting, in such a way,
however, that the shrinkage of the metal, which is preferably lead, tends to bind it
tightly on the carbon.
According to my invention, the carbon fragments are cut or grooved by means
of a saw, or narrow emery wheel, transversely on their edges. They are then
placed side by side, with the grooves in line, and covered with sand, leaving, how-
ever, a narrow trough or channel near the grooved portion of the carbon pieces.
Into this channel is poured molten lead, which sets, and forms a solid bar B,
connecting all the carbons A together, gripping, as it cools and shrinks, a portion
of each.

page_text: In Fig. 2, a pair of grooves are shewn cut in the carbon, leaving a dove-tail
upstanding between them, which is embedded in the solid lead.
In Fig. 3, there is but one cut, which holds a portion or neck of lead, connecting
portions on either side of the carbon fragment. In either case, the lead is locked
around a portion of carbon, so that it cannot get loose and fall.
In Fig. 4, a whole electrode is shewn, made from one piece only of carbon,
transversely cut, with grooves which engage with plugs or blocks of cast lead, to
which screws or bolts are attached, for suspending the electrode from the cover of
the tank. The bars B, in each case, may be provided with such bolts or screws
for suspending the electrodes.
In this manner, I am able to produce, at a low cost for manipulation and manu-
facture, an electrode of gas retort carbon suitable for use in the decomposition of
solutions by electrolysis, on a practical and commercial scale.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
An electrode for electrolytic purposes consisting of fragments of gas retort carbon
grooved and connected by metal attachments, substantially as shewn and described.
Dated this 5th day of August 1893.
NEWTON & SON,
Agents for the Applicant.