IMPROVEMENTS IN THE MANUFACTURE OF SALTS OF SODA
Year: 1878

page_text: LETTERS PATENT to Albert Cahen, of Boulevard Saint Denis, No. 1, at Paris,
Civil Engineer and Patent Agent, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF SALTS OF SODA." A communication from Le Comto
Charles de Montblanc and Lucien Gaulard, of Paris.
PROVISIONAL SPECIFICATION left by the said Albert Cahen at the Office
of the Commissioners of Patents on the 21st November 1878.
ALBERT CAHEN, of Boulevard Saint Denis, No. 1, at Paris, Civil Engineer and
Patent Agent. "IMPROVEMENTS IN THE MANUFACTURE OF SALTS OF SODA." [A
communication from Le Comte Charles de Montblanc and Lucien Gaulard, of
Paris.]
Various apparatus have been constructed for applying the reaction of carbonate
of ammonia upon chloride of sodium to the manufacture of salts of soda. The
processes actually in use failing to give sufficiently satisfactory results, the following
method of manufacture is now proposed and forms the subject of the present
Invention.
For clearness of description the mode of operation is divided into two parts.
First. Solution of the chloride of sodium and saturation of this solution with
ammonia.
Second. Saturation of the mixture thus obtained with carbonic acid, which
saturation determines the formation of bi-carbonate of soda insoluble in presence
of the soluble hydro-chlorate of ammonia.
I will first describe the apparatus for dissolving the chloride of sodium and for
saturating it with ammoniacal gas.
The chloride of sodium is introduced into a vessel of sheet iron, into which an
immersed tube allows of the introduction of water at its bottom. This intro-
duction is regulated by a cock provided with a float, the use of which is hereinafter
mentioned.

page_text: The vessel is placed in a larger vessel of sheet iron or of wood in permanent
communication by upper and lower pipes with a third vessel of the same height
and placed in the same horizontal plane.
Under these conditions the solution of chloride of sodium under operation in the
first vessel will overflow and take the same level in the other vessels.
When this level reaches the upper communicating pipe the float acting auto-
matically stops the entrance of the water by the immersed tube.
By means of a cock fitted to the third vessel the solution of chloride of sodium
is introduced by an immersed tube into a receiver.
This receiver is cylindrical and is made of sheet iron; it is divided horizontally
by partitions provided with small communicating tubes or passages placed alter-
nately to the right and left of the apparatus; at its upper part are a pressure gauge
and a cock.
The
There is a tube at the side of the apparatus to empty the saturated solution into
the feeding vessel of the apparatus which forms the subject of the second part of
this description. A column at the side of the apparatus allows by means of a cock
of putting all the compartments in direct communication with each other.
whole of the apparatus can be immersed in a tank filled, with cold water, which
permits the heat developed in the formation of the ammoniacal sodic solution to be
absorbed.
The ammoniacal gas is introduced by a rose, and saturates the solution of chloride
of sodium contained between the bottom of the apparatus and the first partition,
then exerting pressure until the level of the liquid falls below the communicating
tube, it passes out by this latter and saturates the liquid contained in the
partition next above, and so on, until the last layer of liquid having been saturated,
the gas exerts its pressure upon the gauge and indicates that the operation is
finished.
I will now describe the series of apparatus in which are effected the saturation
with the carbonic acid, and consequently the precipitation of the bi-carbonate of
soda.
It is thus proposed to effect an uninterrupted manufacture by preventing the
drawing off by the non-utilized gases of a portion of the ammonia or even of the
carbonate of ammonia.
These apparatus which communicate with each other so that they can be taken
successively in order are alike. They comprise a cast iron cylinder in which is a
hollow central shaft of cast or wrought iron, provided at its bottom with beaters
or agitators capable of being driven by bevel gearing. This hollow shaft which
has holes at its bottom admits a current of carbonic acid regulated by a cock.
An immersed tube provided with a cock allows of the communication of the
apparatus with the feeding vessel which contains the mixture prepared in the
apparatus first hereinbefore described.
Cocks placed upon the pipe for distributing the carbonic acid allow of the
direct introduction of this gas successively into each apparatus. There are man-
holes for removing the bicarbonate of soda.
The several apparatus are in communication one with another by a tube; this
communication is permitted by cocks, according to the requirements of the operation,
from the upper or the lower portion of the apparatus.
There are movable gratings or strainers to prevent the passage through these
cocks of anything but the liquid portion of the product of one apparatus into that
next following.
I will describe the action in the first apparatus of the series.
The cock communicating between the lower part and the second apparatus is
closed. The cock at the top of the hollow shaft and that communicating between
the upper part and the second apparatus are open. The liquid mixture of chloride
of sodium and ammonia and the carbonic acid gas enter the apparatus simul
taneously. The precipitation of the bi carbonate of soda takes place, and the shaft
being put in motion, it follows that the precipitated salt is thrown against the

page_text: sides of the apparatus, and cannot obstruct the holes by which the carbonic acid
gas is introduced.
The level of the liquid will rise to the upper cock, by which it will run into the
second apparatus, whilst the non-utilized gas drawing away a certain quantity of
ammonia, acts while passing through an opening at the top upon the incompletely
decomposed liquid.
The two elements, gas and liquid, pass thus successively into the second and
following apparatus; it will be understood that the liquid collected in a pipe
leading from the lower part of the apparatus will be pure hydro-chlorate of
ammonia, and that the gas escaping will not contain either free carbonic acid or
transammoniacals.
When the apparatus No. 1 is sufficiently charged with bicarbonate of soda the
requisite cocks are closed and the cock at the lower part is opened; in consequence
of the pressure exerted by the carbonic acid gas the liquid only of No. 1 apparatus
is emptied into No. 2 apparatus, the lower cock is then closed, and a cock is opened
to admit the carbonic acid gas directly into No. 2 apparatus, which now takes the
place of No. 1.
The manhole of the first apparatus can then be opened and the dry bicarbonate
of soda removed. This operation being finished this apparatus then becomes the
last of the series. It will thus be seen that this arrangement allows of the uninter-
rupted saturation of the ammoniacal sodic liquor.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Albert Calen in the Great Seal Patent Office on the 17th May 1879.
ALBERT CAHEN, of Boulevard Saint Denis, No. 1, at Paris, Civil Engineer and
Patent Agent.
"IMPROVEMENTS IN THE MANUFACTURE OF SALTS OF SODA."
A communication by Le Comte Charles de Montblanc and Lucien Gaulard, of
Paris.
Various apparatus have been constructed for applying the reaction of carbonate
of ammonia upon chloride of sodium to the manufacture of salts of soda. The
processes actually in use failing to give sufficiently satisfactory results, the following
method of manufacture is now proposed and forms the subject of the present
Invention.
For clearness of description the mode of operation is divided into two parts.
First. Solution of the chloride of sodium and saturation of this solution with
ammonia.
Second. Saturation of the mixture thus obtained with carbonic acid, which
saturation determines the formation of bi-carbonate of. soda insoluble in presence
of the soluble hydrochlorate of ammonia.
I will first describe the apparatus for dissolving the chloride of sodium and for
saturating it with ammoniacal gas. This apparatus is represented in Figure 1 of
the annexed Drawings.
The chloride of sodium is introduced into a vessel a of sheet iron, into which an
immersed tube p allows of the introduction of water at its bottom. This intro-
duction is regulated by a cock provided with a float f, the use of which is
hereinafter mentioned.
The vessel a is as seen in the Figure placed in a larger vessel b of sheet iron or
of wood, in permanent communication by the pipes d and e with a third vessel c of
the same height, and placed in the same horizontal plane.
Under these conditions the solution of chloride of sodium under operation in the
vessel a will overflow and take the same level in the vessels b and c.
When this level reaches the communicating pipe e, the float f acting auto-
matically stops the entrance of the water by the tube p.
By means of a cock fitted to the vessel c the solution of chloride of sodium is
introduced by an immersed tube t into a receiver h.
This receiver h is cylindrical and is made of sheet iron; it is divided by hori-
zontal partitions n, provided with small communicating tubes or passages u, placed
alternately to the right and left of the apparatus; at its upper part are a pressure
gauges and a cock 2.
There is a tube o at the side of the apparatus to empty the saturated solution
into the feeding vessel of the apparatus which forms the subject of the second part
of this description. A column at the side of the apparatus allows by means
of a cock v of putting all the compartments in direct communication with each
other. The whole of the apparatus can be immersed in a tank filled with cold
water which it has not been thought necessary to shew, and which permits the
heat developed in the formation of the ammoniacal sodic solution to be absorbed.
The ammoniacal gas is introduced by a rose g and saturates the solution of
chloride of sodium contained between the bottom of the apparatus and the first
partition n, then exerting pressure until the level of the liquid falls below the
tube u, it passes out by this latter and saturates the liquid contained in the division
next above, and so on, until the last layer of liquid having been saturated, the gas
exerts its pressure upon the gauge 8 and indicates that the operation is finished.
I will now describe the series of apparatus in which are effected the saturation
with the carbonic acid, and consequently the precipitation of the bi-carbonate of
soda. These apparatus are represented in Figures 2 and 3. It is thus proposed
to effect an uninterrupted manufacture by preventing the drawing off by the non
utilized gases of a portion of the ammonia or even of the carbonate of ammonia.

page_text: These apparatus which communicate with each other so that they can be taken
successively in order are alike. They comprise a cast iron cylinder A in which is
a hollow central shaft s of cast or wrought iron provided at its bottom with beaters
or agitators capable of being driven by bevel gearing e. This hollow shaft which
has holes u at its bottom admits a current of carbonic acid regulated by a cock g.
An immersed tube c provided with a cock d allows of the communication of the
apparatus with the feeding vessel, which it has not been thought necessary to shew,
and which contains the mixture prepared in the apparatus shewn in Figure 1.
Cocks placed upon the pipe for distributing the carbonic acid allow of the
direct introduction of this gas successively into each apparatus. There are man-
holes o for removing the bicarbonate of soda.
The several apparatus are in communication one with another by a tube b; this
communication is permitted by cocks m and v, according to the requirements of the
operation from the upper or the lower portion of the apparatus.
There are movable gratings or strainers n to prevent the passage through the
cocks m and v of anything but the liquid portion of the product of one apparatus
into that next following. The construction of these strainers is clearly shewn in
the detail views Figure 4.
I will describe the action in the first apparatus of the series.
The cocks h and vare closed. The cocks and m are open. The liquid mixture
of chloride of sodium and ammonia and the carbonic acid gas thus enter the
apparatus simultaneously. The precipitation of the bicarbonate of soda takes place,
and the shaft s being put in motion, it follows that the precipitated salt is thrown
against the sides of the apparatus and cannot obstruct the holes u by which the
carbonic acid gas is introduced.
The level of the liquid will rise to the cock m by which it will run into the
second apparatus, whilst the non-utilized gas drawing away a certain quantity of
ammonia, acts while passing through the opening fat the top upon the incompletely
decomposed liquid.
The two elements, gas and liquid, pass thus successively into the second and
following apparatus, 2, 3, 4, &c.; it will be understood that the liquid collected in x
will be pure hydro-chlorate of ammonia, and that the gas escaping will not contain
either free carbonic acid or transammoniacals.
When the apparatus No. 1 is sufficiently charged with bicarbonate of soda, the
cocks d, m, and fare closed and the cock v is opened; in consequence of the pressure
exerted by the carbonic acid gas, the liquid only of No. 1 apparatus is emptied by
the pipe p into No. 2 apparatus, the cock v is then closed and the cock his opened
to admit the carbonic acid gas directly into No. 2 apparatus, which now takes the
place of No. 1.
The manhole of the first apparatus can then be opened and the dry bi-carbonate
of soda removed. This operation being finished this apparatus then becomes the
last of the series. It will thus be seen that this arrangement allows of the
uninterrupted saturation of the ammoniacal sodic liquor.
And having now described the nature of the said Invention, and in what manner
the same is to be performed, I declare that I claim,-
The manufacture of salts of soda in the manner and by apparatus arranged and
acting substantially as hereinbefore described.
In witness whereof, I, the said Albert Caben, have hereunto set my hand
and seal, this Fourteenth day of May, One thousand eight hundred and
seventy nine.
ALBERT CAHEN. (L.S.)