An Improved Electrolytic Apparatus.
Year: 1899

page_text: Date of Application, 8th June, 1899-Accepted, 11th Nov., 1899
An Improved Electrolytic Apparatus.
We, TRANQUILLE MICHEL, IVAN WILHELM, and HILDEBERT RICHARD, all of
Aix, Bouche du Rhone, France, Engineers, 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 an electrolytic apparatus divided into two fluid
tight compartments in one of which the properly so-called electrolytic work takes
place and in the other the reactions which complete the treatment are effected.
This apparatus is especially destined for the electrolysis af alkaline chlorides and
particularly chloride of sodium with a view to the simultaneous production of
chlorine and of soda.
In electrolysing in general and particularly in the electrolysing of chloride of
sodium the separated elements have a tendency to recombine in order to form
the original body or intermediary compound ones which are without value for
the purpose aimed at in the operation.
The invention consists in subtracting one of the separated elements from the
re-actions which are being produced in the electrolytic bath, by transferring it,
by means of an intermediary electrode into a special compartment where it
undergoes the re-actions which compose the process and which, further, permits
of the energy produced by these re-actions contributing to the electrolytic work.
The annexed drawing shows, by way of example, one mode of constructing the
apparatus for effecting the object of our invention.
This apparatus, represented in a vertical section, is more particularly destined
for the electrolysis of chloride of sodium.
It is composed of a tub o divided into two compartments m n by a partition B
which does not reach to the bottom of the tub but plunges into a bath of mercury r
which lies at this spot so that the two compartments are quite fluid tight.
At the two ends of the partition b, rollers s s¹ are mounted, over which an end-
less band d passes, said band forming the intermediary electrode and being, by
preference, made of wire gauze; this band is also guided by the rollers 2 st gu
and passes from one compartment into the other through the mercury bath.
The compartment m receives the solution to he electrolysed (in this case a
solution of sea salt) and the anode a; the compartment a receives the cathode c
and the required re-agent (in this case a diluted solution of soda)..
A partition. 7 which has an india-rubber band resting on the band d cuts
off communication between the compartments at the upper part of the tub.
The tub can be covered with a cover provided with openings ef for the passage
of the gases. The walls of the tub can also be provided with tubes 1, 2, 3, 4, by
means of which several apparatuses can be joined together for the purpose of
producing a circulation of the liquids which favours the electrolytic work.
In the compartment m, or electrolysis compartment, the separation of the
elements is produced of which one, the chlorine, goes to the anode and escapes
by the openinge whilst the other, the sodium, passes to the band d which serves
as the cathode where it becomes amalgamated with the mercury and is trans-
ported into the compartment n, or the re-action compartment, where the sodium
is oxidised, in decomposing the water in order to form soda, whilst the hydrogen
is liberated and escapes through the opening f. The mercury will return with

page_text: the band d, which has just been working as the anode into the mercury bath
and then again into the compartment m to re-form the amalgam.
An economical advantage of this apparatus, in its application to the electro-
lysis of chloride of sodium, is that it does not require the use of a large quantity
of mercury the latter being continually amalgamated and disamalgamated during
the movement of the intermediary electrode.
The manner in which the energy produced by the reactions in the second com-
partment are made to assist in the electrolytic work may be stated as follows:-
The electric energy necessary for the electrolysis decomposes itself into two
parts, the one serving to overcome the resistance of the electrolyte and the other
to perform the molecular segregation of the solution. Further this second part
of the electric energy, being absorbed by the electrolytic decomposition, is resti-
tuted when some chemical combination of the decomposed elements are produced'
so that the spent energy is reduced to the part necessary to overcome the resistance
of the electrolyte. It can be said, as a consequence, that the energy resulting
from the chemical reactions contributes to the electrolytic work since that they
restitute the electric energy used in the electrolytic decomposition. This is the
case in the electrolysis of chloride of sodium by means of a cathode in mercury
when the oxygen of the water combines with the sodium of the amalgam of
sodium to form caustic soda.
If this combination or reaction (producing caustic soda) were to be produced
outside of the apparatus then the energy resulting from the chemical reactions
would be lost for the electrolytic work the latter absorbing in this case, the whole
of the electric energy without any restitution. In the procedure of the present
invention the energy resulting from the chemical reactions produced in the second
compartment is not lost for the electrolytic work, but, on the contrary, the part
of the electric energy absorbed by the electrolytic decomposition is restored to
the electric current upon its passage in order to produce these reactions, and this
because the two compartments of the apparatus are electrically connected.
It can be therefore said that the energy resulting from the reactions produced
in the second compartment contributes to the electrolytic work.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we consider novel and desire to claim is :---
1. An electrolytic apparatus characterized by the use of an intermediary elec-
trode which carries its anions from one of the fluid tight compartments of the
apparatus into the other in order to avoid producing useless re-actions of the
electrolyte and to make the energy which results from the re-actions (fore-seen
and predetermined to take place in the second compartment) assist in the electro-
lytic work, substantially as herein before described.
2. In an electrolytic apparatus such as claimed in Claim 1, the application and
use of an intermediary electrode consisting of an endless metallic band which is
located between the two principal electrodes and kept constantly in motion said
band dipping into a mercury bath which is arranged to form a seal between the
compartments of the apparatus, substantially as and for the purpose herein before
set forth.
3. The construction or general arrangement and combination of parts of the
apparatus substantially as herein before described and shown in the drawing
annexed.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.