Improvements in or relating to the Electrolysis of Salts in Solution and Apparatus therefor.
Year: 1899

page_text: Date of Application, 18th Feb., 1899
Complete Specification Left, 23rd Oct., 1899-Accepted, 23rd Dec., 1899
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Electrolysis of Salts in Solution
and Apparatus therefor.
We, ANTOINE JOSEPH OUTHENIN CHALANDRE, LOUIS JEAN BAPTISTE AUGUSTIN
COLAS and CHARLES JULES GÉRARD, Engineers, all of 16, Rue Notre Dame des
Victoires, l'aris, in the Republic of France, do hereby declare the nature of this
invention to be as follows:--
In the electrolysis of soluble salts and, especially, of alkaline chlorides, it is a
well known fact, that the electric current will have the effect, in cases when the
electrolyte consists of a liquid solution of, for example, chloride of sodium, of
forming:
1). At the cathode:
() A solution of caustic soda, produced by the sodium of the salt combining
with oxygen which is furnished by the water of the electrolyte, while the corres-
ponding hydrogen is set free.
(b) The liberation of hydrogen, in consequence of the decomposition of part
of the water of the electrolyte."
2). At the anode;
(c) The liberation of chlorine caused by the decomposition of the salt.
(d) The liberation of oxygen, corresponding to the hydrogen liberated as stated
in (b).
It will be seen therefore that there takes place, in particular, a liberation of
chlorine and of hydrogen.
The present invention relates to an apparatus and a process having the object
of combining the said two gases to form hydrochloric acid, which is discharged into
the electrolyte in order to counteract the secondary reactions arising from chlorine-
oxygen compounds formed in the electrolyser.
In order to render the following description perfectly clear an electrolyser of
any known system provided with the present improvements will be described.
As has been remarked above, the electrolyser itself may be of any construction,
but the one to be described by way of example, is especially adapted for this
invention and has been chosen for the purpose of explaining the invention.
The cathode compartment which is open at its upper end, is provided with a gas
receiver or collector which may rest simply by means of an angle bar on another
angle bar on the casing of the electrolyser. This gas receiver which is open at
its lower end, has at one side a beak or projection on which is fixed a rubber band
forming a joint along the front wall of the tubes of the electrolyser, in order to
ensure all the hydrogen rising from the cathode compartment to enter the receiver
from which it is allowed to pass, through a pipe, to a burner. This burner is com-
pletely surrounded by a glass cylinder like an ordinary lamp glass but closed at
both ends by plates which are connected together by bars, the whole being
preferably surrounded by a close wire netting. At the upper part of this com-
bustion chamber a tube is introduced extending from another tube for collecting
the chlorine gas included in the anode compartment. A pipe enters the bottom
plate of the burner chamber by which the hydrochloric acid, formed by the

page_text: combustion of the hydrogen in the chlorine is carried off, and which discharges
its contents into the circulation tube of the anode liquid.
Having now described all the parts constituting the improved apparatus for the
automatic production of hydrochloric acid, necessary for the suppression of secon-
dary chemical reactions, the actual working of such an apparatus will be
described.
The hydrogen supply tube is provided with a stop-cock or valve of any suitable
kind which is opened on starting the process. The hydrogen gas passes through
this tube into the receiver where it ignites on coming in contact with the chlorine
coming from the anode compartment.
The flow of hydrogen is then regulated by means of the said cock so as to corres-
pond to the production of so much hydrochloric acid as will completely stop
secondary reactions.
The hydrochloric acid escaping through the discharge tube will mix with the
anode liquid which is then taken, by means of a pump back to the electrolyser.
As is well-known the production, as regards quantity, of hydrogen varies with
the progress or action in the electrolyser. The more rapid the action of the elec-
trolyser the greater the quantity of hydrogen given off. It follows therefore that
the pressure of hydrogen in the collector varies according to the work of the electro-
lyser. If its action is rapid the pressure in the collector will be great and a large
amount of hydrogen will enter the burner. Consequently a great quantity of
hydrochloric acid will be formed which returns to the electrolyser. If, on the con-
trary the action of the electrolyser is slow, the quantity of hydrogen formed is small
and the pressure in the collector diminishes correspondingly. A small quantity of
hydrogen passing to the burner and consequently a small quantity of hydrochloric
acid is formed. It is therefore evident that the more rapid the action of the
electrolyser the greater is the quantity of hydrochloric acid produced which returns
to the electrolyser. It can therefore be said that the production of hydrochloric
acid is, in a way regulated by the action of the electrolyte. The apparatus, there-
fore, regulates itself within certain limits.
The receiver can, of course, be of any convenient form as long as it can collect
and keep the evolved gas.
Instead of arranging a generator of hydrochloric acid for every electrolyser it
would be possible to have a combination, and the right of arranging such a
combination is hereby reserved-in which a single generator of hydrochloric acid
may supply several electrolysers.
The above description has been confined to the treatment according to the im-
proved process of alkaline chlorides only; but the invention is quite capable of
being applied to aqueous electrolysis in general.
The final product will perhaps not be hydrochloric acid; still the hydrogen pro-
duced during electrolysis will, in one form or another, be alway returned to the
electrolyser, with the view to counteract secondary reactions.
Dated this 18th day of February 1899
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to the Electrolysis of Salts in Solution
and Apparatus therefor.
We, ANTOINE JOSEPH OUTHENIN CHALANDRE, LOUIS JEAN BAPTISTE AUGUSTIN
COLAS and CHARLES JULES GÉRARD, Engineers, all of 16, 'Rue Notre Dame des
Victoires, Paris, in the Republic of France, do hereby declare the nature of this

page_text: invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement: --
In the electrolysis of soluble salts and, especially, of alkaline chlorides, it is a
well known fact, that the electric current will have the effect in cases when the
electrolyte consists of a liquid solution of, for example, chloride of sodium, of
forming:
1. At the cathode:
(a) A solution of caustic soda, produced by the, sodium of the salt, combining
with oxygen which is furnished by the water of the electrolyte, while the corres-
ponding hydrogen is set free.
(b) The liberation of hydrogen, in consequence of the decomposition of part
on the water of the electrolyte.
2. At the anode:
(c) The liberation of chlorine caused by the decomposition of the salt.
(d) The liberation of oxygen, corresponding to the hydrogen liberated as stated
in (6). It will be seen therefore that there takes place, in particular, a liberation of
chlorine and of hydrogen.
The present invention relates to an apparatus and a process, for producing
soda and chlorine, having the object of combining part of the said two gases to
form hydrochloric acid, which is discharged into the electrolyte in order to
counteract the secondary reactions arising from chlorine-oxygen compounds,
formed in the electrolyser.
In order to render the following description perfectly clear, in the accompany-
ing drawings an electrolyser of any known system provided with the present
improvements is illustrated.
Figure 1 is a general view of the apparatus in elevation.
Figure 2 is an elevation partly in section of the hydrogen receiver for collecting
the hydrogen generated in the cathode compartment of the apparatus.
Figure 3 is a plan of the same and
Figure 4 a cross section on the lines A-B.
Figure 5 is a side view of the electrolyser.
Figure 6 is a cross-section showing the connection between the hydrogen receiver
and the cathode compartment.
Figure 7 illustrates the connection between the admission tube of the hydro-
chloric acid into the circulating tube of the anode liquid.
Figure 8 is a sectional elevation, on the line C-D Fig. 9, of the hydrogen gas
burner in which the hydrochloric acid is formed destined for the anode liquid.
Figure 9 is a plan of the device illustrated in Figure S.
As has been remarked above, the electrolyser itself may be of any construction,
but the one illustrated is especially adapted for this invention and has been chosen
for the purpose of explaining the invention.
The cathode compartment a which is open at its upper end, is provided with a
gas receiver or collector b (Figures 1, 2, 3) which may rest simply, as shown in
Figure 6-by means of an angle bar e on another angle bar d on the casing of the
electrolyser. This gas receiver b, which is open at its lower end, has at one side a
beak or projection e, on which is fixed a rubber band f forming a joint along the
front wall of the tubes of the electrolyser, in order to cause all the hydrogen rising
from the compartment a to enter the receiver b from which it is allowed to pass,
through the pipe g, to the burner. This burner is completely surrounded by a
glass cylinder k, like an ordinary lamp-glass but closed at both ends by plates 7 7,
which are connected together by bars in, the whole being, preferably surrounded by
a close wire netting n. At the upper part of this combustion chamber a tube o is
introduced, extending from another tube for drawing off the chlorine gas evolved
in the anode compartment, to be collected, stored or utilised in any desired manner.
A pipe enters the bottom plate of the burner chamber, by which the hydro-
chloric acid, formed by the combustion of the hydrogen in the chlorine is carried off,
and which discharges its contents at r into the circulation tube of the anode liquid

page_text: Having now described all the parts constituting the improved apparatus for the
automatic production of hydrochloric acid, necessary for the suppression of
secondary chemical reactions, the actual working of such an apparatus will be
described.
The tube g is provided with a stop-cock or valve of any suitable kind, which is
opened on starting the process. The hydrogen gas passes through this tube inte
the receiver where it ignites on coming in contact with a portion of the chlorine
coming from the anode compartment, by way of the tube p.
The flow of hydrogen is then regulated by means of the said cock on the tube g,
so as to correspond to the production of so much hydrochloric acid as will com-
pletely stop secondary reactions.
The hydrochloric acid escaping through the tube will mix with the arede
liquid at which is then taken by means of a pump, back to the electrolyser ut,
where it is introduced at v.
As is well known the production. as regards quantity, of hydrogen varies with
the progress or action in the electrolyser. The more rapid the action of the
electrolyser the greater the quantity of hydrogen given off. It follows therefore,
that the pressure of hydrogen in the collector varies according to the work of the
electrolyser. If its action is rapid the pressure in the collector will be great and
a large amount of hydrogen will enter the burner. Consequently a great quantity
of hydrochloric acid will be formed which returns to the electrolyser. If, on the
contrary the action of the electrolyser is slow, the quantity of hydrogen formed is
small and the pressure in the collector diminishes correspondingly. A small
quantity of hydrogen passing to the burner and consequently a small quantity of
hydrochloric acid is formed. It is therefore evident that the more rapid the action
of the electrolyser the greater is the quantity of hydrochloric acid produced which
returns to the electrolyser. It can therefore be said that the production of hydro-
chloric acid is, in a way regulated by the action of the electrolyte. The apparatus,
therefore, regulates itself within certain limits.
The receiver can, of course, be of any convenient form as long as it can collect
and keep the evolved gas.
•
Instead of arranging a generator of hydrochloric acid for every electrolyser it
would be possible to have a combination and the right of arranging such a com-
bination is hereby reserved-in which a single generator of hydrochloric acid
may supply several electrolysers.
The above description has been confined to the treatment according to the im-
proved process of alkaline chlorides only; but the invention is quite capable of
being applied to aqueous electrolysis in general.
The final product will perhaps not be hydrochloric acid; still the hydrogen
produced during electrolysis will, in one form or another, be always returned to
the electrolyser, with the view to counteract secondary reactions.
Having now particularly described and ascertained the nature of our said in-
vention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. A process for the purpose of counteracting the secondary reactions arising in
an electrolyser consisting in combining portions of the different gases evolved both
in the cathode and anode compartments of an electrolyser and reintroducing them
in their combined state, into the electrolyser, substantially as described.
2. Apparatus by means of which the process as indicated in Claim 1 can be
carried out in the case of alkaline chlorides, and, especially, of chloride of sodium,
which apparatus may be combined with one or more electrolysers comprising a
receiver or device capable of collecting and storing the hydrogen gas produced a
.connection between said receiver and a burner or combustion space closed on
all sides in which part of the chlorine gas produced is also admitted whereby owing
to the combustion of said gases hydrochloric acid is formed, and means for intro-
ducing said acid into the electrolyser substantially as described.

page_text: 3. In apparatus of the kind described means for regulating automatically the
introduction of the hydrochloric acid produced, into the electrolyser, substantially
as described.
4. The complete electrolysing apparatus substantially as described or illustrated
in the accompanying drawing.
Dated this 16th day of October 1800