IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR MANUFACTURING SODA BY THE AMMONIA METHOD
Year: 1881

page_text: In the Matter of Letters Patent granted to John Imray of No 28.
Southampton Buildings Chancery Lane in the County of Middlesex, for
the Invention of "IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR
MANUFACTURING SODA BY THE AMMONIA METHOD a communication to
him from abroad by La Société Anonyme des Produits Chimiques du
Sud-Ouest, of Paris, France, an Incorporated Company, bearing date the
14th day of October 1881 No 4401
"
DISCLAIMER AND MEMORANDUM OF ALTERATION as proposed to be
entered by the said John Imray pursuant to the Statutes in that case made
and provided.
WHEREAS Her Majesty Queen Victoria by Her Letters Patent under the
Great Seal of the United Kingdom of Great Britain and Ireland bearing date at
Westminster the Fourteenth day of October 1881 No 4491 in the Forty-fifth
year of Her Reign did give and grant unto me the said John Imray my executors
adininistrators and assigns, the sole privilege for the term of fourteen years, thence
next ensuing, of making using, exercising, and vending within the United
Kingdom of Great Britain and Ireland the Channel Islands and Isle of Man the
said Invention of "IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR MANU-
FACTURING SODA BY THE AMMONIA METHOD" a communication to me from Abroad
by La Société Anonyme des Produits Chimiques du Sud-Ouest, of Paris, France,
an Incorporated Company.
And whereas in pursuance of a proviso in the said Letters Patent contained I
the said John Imray did within six calendar months next after the date of the said
Letters Patent cause a Specification or Instrument in writing under my hand and
seal purporting to describe and ascertain the nature of the said Invention and in
what manner the same was to be performed, to be duly filed in the Great Seal
Patent Office.
And whereas since the filing of the said Specification I the said John Imray

page_text: (1st) Operation.-A saturated solution of sodium chloride is introduced into a
number of cylindrical vessels constituting a battery, such as those marked 1, 2, 3,
4, 5, on the accompanying drawing, the vessels being of small diameter so as to be
readily cooled to a very low temperature, and each vessel being only about two
thirds filled. Each cylinder has a central tubular shaft with perforations through
which the gas is introduced into the liquid. The gas may however be introduced
by any other suitable means, provided that it passes into the liquid in a state of
subdivision and that the communicating pipes are connected to the space above
the liquid of the one vessel and pass to the body of the liquid in the next vessel.
The hollow shaft is capable of rotation, and is provided with arms for stirring up
the precipitated matter at certain intervals.
The gas disengaged from the first cylinder (cylinder No 1) passes through the
communicating pipe, at the top which is connected to the hollow shaft of cylinder
No 2 and in like manner the gases are made to pass from No 2 into No 3, and
so on.
If ammoniacal gases from the regenerating apparatus are introduced through
the hollow shaft of cylinder No 1, the aminonia and carbonate of ammonia
disengaged therefrom first saturate the contents of this cylinder to a certain extent
and then pass to cylinder No 2, the operation being continued until the total
quantity of liquid contained in the cylinders of the battery contains an average of
10 per cent of ammonia, (N H³). The contents of each vessel varies in the
proportion of ammonia, the first being saturated, while the following ones are
gradually weaker and weaker.
2nd Operation.This consists in replacing in cylinder No 1 the supply of
ammoniacal gas by a strong current of impure carbonic acid coming from a lime
kiln, this operation being continued until the degree of simple carbonization has
been slightly passed, that is to say, until sesqui-carbonate commences to be formed.

page_text: This is effected, like the following operations, under pressure; a simple water
column pressure is sufficient for a good utilisation of the gases, and experiment has
shewn that a maximum height of three feet of water is sufficient for preventing
appreciable losses of carbonic acid. Under the above conditions the current of
impure carbonic acid gas acts as follows:- Arriving in a very rich ammoniacal
solution it carries with it a notable quantity of greatly hydrated ammonia, with
which it unites in gaseous form in the upper space of the cylinder. A portion of
the carbonate of ammonia formed falls into the liquid again, where it is dissolved,
while the excess passes into the following cylinders.
3rd Operation. Each cylinder of the battery has a discharge pipe and cock of
equal sectional area, and each of these pipes opens into a horizontal main collecting
pipe, by which means, although the contents of each vessel is of variable strength,
a total discharge of uniform mean strength is obtained The ammoniacal liquor
obtained as above described passes from the collecting pipe into a series of small
batteries, consisting each of two cylinders, similar to those above described, with
the difference that the cylinder B of each set is placed underneath the cylinder A.
The upper cylinder A is filled to about three fourths of its capacity, while the lower
cylinder is left quite empty. The upper cylinder A has a pipe from its top dipping
down into water to form a seal of about 3 fect column. Into the lower vessel B is
introduced the pure carbonic acid resulting from the calcination of the bicarbonate
of soda, and as this vessel has a pipe from its top communicating with the hollow
shaft of the upper vessel, the carbonic acid ascends into the cylinder A, where it is
readily absorbed by the liquid, so long as this contains only sesqui carbonate and
even a small quantity of bicarbonate. This is continued under agitation until tho
gas begins to escape past the liquid seal. The operation proceeds in the cylinder A
very much in the same way as in the previous case, that is to say, the carbonic
acid passing into the shallow layer of liquid carries with it carbonate of ammonia,
with which it unites in gaseous form and falls back into the liquid where it
dissolves.
4th. Operation. The liquid in the upper cylinder A containing mostly sesqui
carbonate, is now run into the vessel B, to be there bi-carbonated by the pure
carbonic acid from calcination, the surplus of the gas passing through to the upper
vessel, which is recharged with liquid to be sesqui carbonated as above described.
The bi carbonisation is consequently obtained by an excess of gas which is utilised
in the upper cylinder. The bi carbonate from the lower vessel is treated in a
centrifugal machine or filter press to clear it of the ammoniacal mother liquor.
5th Operation. The regeneration of the ammonia contained in the nother liquors is
effected by distillation.
From what has preceded it will be seen that in the second operation the impure
gases from the lime kilns are deprived of their carbonic acid by their passage,
through the cylinders, and that, it is principally in the gaseous state that this
carbonic acid combines with the greatly hydrated ammonia, carried forcibly along
by the mass of gases.
In the 3rd Operation the pure carbonic acid coming from soda calcining kilns
carries into the upper space of cylinder A a part of the carbonate of ammonia, with
which it also unites in a gascous condition. Lastly, in the fourth operation the
bicarbonisation of the liquids contained in the cylinder B is obtained by an excess
of pure carbonic acid, of which the surplus is also usefully employed in the
cylinder A.
Having thus described the nature of the said invention and in what manner the
same is to be performed, as communicated to me by my foreign correspondents, I
claim:-
First. The herein described process for manufacturing soda by the ammonia.
method, wherein carbonic acid is caused to unite with ammonia or its volatile
compounds in a gaseous condition, the reacting gases being for this purpose applied
in a bighly hydrated condition.

page_text: Second. The use of apparatus for the manufacture of soda by the ammonia method,
arranged and operating as herein described.
In witness whereof I the said John Imray have hereunto set my hand and
seal, this Twelfth day of April in the year of our Lord One thousand eight
hundred and eighty-two.
Second. The use of apparatus for the manufacture of soda by the ammonia method,
arranged and operating as herein described.
In witness whereof I the said John Imray have hereunto set my hand and
seal, this Twelfth day of April in the year of our Lord One thousand eight
hundred and eighty-two.
JOHN IMRAY (L.S.)
In witness whereof I the said John Imray have hereunto set my hand and
seal this ninth day of November in the year of our Lord One thousand
To the Commissioners of Patents for Inventions.
I hereby grant my Fiat giving leave to the within named John Imray, to file in
the Office of the Commissioners of Patents for Inventions, with the Specification 1
to which the same relates, the within written Disclaimer and Memorandum of
Alteration.

page_text: LETTERS PATENT to John Imray, of No. 28, Southampton Buildings, Chancery
Lane, in the County of Middlesex, for an Invention of "IMPROVEMENTS IN
THE PROCESS AND APPARATUS FOR MANUFACTURING SODA BY THE AMMONIA
METHOD." A communication from abroad by La Société Anonyme des
Produits chimiques du Sud-Ouest, of Paris, France, an Incorporated
Company.
PROVISIONAL SPECIFICATION. left by the said John Imray at the Office of
the Commissioners of Patents on the 14th October 1881.
JOHN IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of Middlesex. "IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR
MANUFACTURING SODA BY THE AMMONIA METHOD." [A communication from
abroad by La Société Anonyme des Produits Chimiques du Sud-Ouest, of Paris,
France, an Incorporated Company.]
In manufacturing soda by the ammonia method, gaseous carbonic acid is made
to react on a solution of ammoniacal sodium chloride, but as the gas rapidly passes
through the liquid, it is necessary, especially towards the end of the process, to
employ it under great pressure, which involves strong and expensive apparatus.
This Invention relates to a method of effecting the required reaction by exposing
the ammonia greatly hydrated and in the gaseous condition to the carbonic acid in
the like condition, so that their mixture and mutual reaction are greatly facilitated.
The process for this purpose, independently of the filtration, washing, and
calcination of the resulting bicarbonate of soda consists of five operations.
(1.) Preparation of the ammoniacal mother liquor.
(2.) Carbonation.
(3.) Transformation into sesqui carbonate.
(4.) Bicarbonation.
(5.) Regeneration.
(1.) A saturated solution of sodium chloride is introduced into a number of
india waale confituing latton heal haine about time inde Allal

page_text: hollow shaft of the vessel next in order, so that the gas disengaged from the first
vessel is made to pass through the liquid in the second, and so on throughout the
battery. The ammoniacal gases resulting from the regenerating apparatus being
introduced by the hollow shaft into the first vessel, act therein and then pass to
the second, and so on, and this action is maintained until the total of the liquid in
all the vessels contains about 10 per cent. of ammonia, the contents of each however
being rich in ammonia in different degrees, the first having most and the others
less and less in order.
(2.) Instead of the ammoniacal gases a strong current of impure carbonic acid,
such as is produced from lime kilns, is now introduced into the first vessel until
the stage of carbonation is passed and that of bi-carbonation begins.
Very little
pressure is required in this operation, not exceeding three feet of water column.
The carbonic acid in passing through the rich ammoniacal solution carries with it
a considerable quantity of greatly hydrated ammonia; a portion of this becomes
carbonated in the upper part of the vessel and falls into the liquid in which it is
dissolved, whilst the rest passes on to the succeeding vessels.
(3.) Each of the vessels having a discharge cock at the bottom communicating
with a common pipe, liquid of average strength is got in the pipe by running into
it so much from one and so much from another. This liquid is conducted to vessels
like those above described, arranged in pairs the one above the other. The upper
vessel is charged about three fourths. It has a pipe from its top dipping down in
water to form a seal of about 3 feet column. Into the lower vessel is introduced
the pure carbonic acid resulting from the calcination of the bicarbonate of soda;
and as this vessel has a pipe from its top communicating with the hollow shaft of
the upper vessel, the carbonic acid ascends and becomes absorbed in the liquid in
the upper vessel. This is continued under agitation till the gas begins to escape
past the liquid seal.
(4.) The liquid in the upper vessel, containing mostly sesqui carbonate, is now
run into the lower vessel to be bicarbonated by the pure carbonic acid from
calcination, the surplus of the gas passing through the upper vessel, which is
recharged with liquid to be sesqui carbonated as above described. The bicarbonate
from the lower vessel is treated in a centrifugal machine or filter press to clear it
of the ammoniacal mother liquor.
(5.) The regeneration of the ammonia contained in the mother liquors is effected
by distillation.
From what has preceded it will be seen that the carbonic acid in several of the
operations described is brought to act not only on the liquid but also on the
hydrated ammonia in a quasi gaseous condition, in which condition, corresponding
nearly with that of the carbonic acid gas, a more intimate mixture and more
complete and rapid reaction are ensured.
Also, in the fourth operation the surplus of pure carbonic acid supplied in
abundance for bi carbonation in the lower vessels is fully utilised for sesqui-
carbonation in the upper vessels.

page_text: (5.) Regeneration.
(1st) Operation.-A saturated solution of sodium chloride is introduced into a
number of cylindrical vessels constituting a battery, such as those marked 1, 2, 3,
4, 5, on the accompanying Drawing, the vessels being of small diameter, so as to be
readily cooled to a very low temperature, and each vessel being only about two.
thirds filled. Each cylinder has a central tubular shaft with perforations through
which the gas is introduced into the liquid. The gas may however be introduced
by any other suitable means, provided that it passes into the liquid in a state of
subdivision, and that the communicating pipes are connected to the space above
the liquid of the one vessel and pass to the body of the liquid in the next vessel.
The hollow shaft is capable of rotation, and is provided with arins for stirring up
the precipitated matter at certain intervals.
The gas disengaged from the first cylinder (cylinder No. 1) passes through the
communicating pipe, at the top which is connected to the hollow shaft of
cylinder No. 2, and in like manner the gases are made to pass from No. 2 into
No 3, and so on.
If ammoniacal gases from the regenerating apparatus are introduced through the
hollow shaft of cylinder No. 1, the ammonia and carbonate of ammonia disengaged
therefrom first saturate the contents of this cylinder to a certain extent, and then
pass to cylinder No. 2, the operation being continued until the total quantity of
liquid contained in the cylinders of the battery contains an average of 10 per cent.
of ammonia (N H³). The contents of each vessel varies in the proportion of
ammonia, the first being saturated, while the following ones are gradually weaker
and weaker.
•
2nd Operation. This consists in replacing in cylinder No. 1 the supply of
ammoniacal gas by a strong current of impure carbonic acid coming from a lime

page_text: kiln, this operation being continued until the degree of simple carbonisation has
been slightly passed, that is to say, until sequi carbonate cominences to be formed.
This is effected, like the following operations, under pressure; a simple water
column pressure is sufficient for a good utilisation of the gases, and experiment has
shewn that a maximum height of three feet of water is sufficient for preventing
appreciable losses of carbonic acid. Under the above conditions the current of impure
carbonic acid gas acts as follows:-Arriving in a very rich ammoniacal solution,
it carries with it a notable quantity of greatly hydrated ammonia, with which it
unites in gaseous form in the upper space of the cylinder. A portion of the
carbonate of ammonia formed falls into the liquid again, where it is dissolved,
while the excess passes into the following cylinders.
E
3rd Operation. Each cylinder of the battery has a discharge pipe and cock of
equal sectional area, and each of these pipes opens into a horizontal main collecting
pipe, by which means, although the contents of each vessel is of variable strength,
a total discharge of uniform mean strength is obtained. The ammoniacal liquor
obtained as above described passes from the collecting pipe into a series of small
batteries; consisting each of two cylinders, similar to those above described, with
the difference that the cylinder B of each set is placed underneath the cylinder A.
The upper cylinder A is filled to about three fourths of its capacity, while the
lower cylinder is left quite empty. The upper cylinder A has a pipe from its top
dipping down into water to form a seal of about 3 feet column. Into the lower
vessel B is introduced the pure carbonic acid resulting from the calcination of the
bicarbonate of soda; and as this vessel has a pipe from its top communicating with
the hollow shaft of the upper vessel, the carbonic acid ascends into the cylinder A,
where it is readily absorbed by the liquid, so long as this contains only sequi
carbonate and even a small quantity of bi carbonate. This is continued under
agitation until the gas begins to escape past the liquid seal. The operation proceeds
in the cylinder A very much in the same way as in the previous case, that is to
say, the carbonic acid passing into the shallow layer of liquid carries with it
carbonate of ammonia, with which it unites in gaseous form and falls back into the
liquid, where it dissolves.
4th Operation. The liquid in the upper cylinder A, containing mostly sesqui
carbonate, is now run into the vessel B, to be there bi carbonated by the pure
carbonic acid from calcination, the surplus of the gas passing through to the upper
vessel, which is recharged with liquid to be sesqui carbonated as above described.
The bi carbonisation is consequently obtained by an excess of gas which is utilised
in the upper cylinder. The bi carbonate from the lower vessel is treated in a
centrifugal machine or filter press to clear it of the ammoniacal mother liquor.
5th Operation. The regeneration of the ammonia contained in the mother liquors
is effected by distillation.
From what has preceded it will be seen that in the second operation the impure
gases from the lime kilns are deprived of their carbonic acid by their passage
through the cylinders, and that it is principally in the gascous state that this
carbonic acid combines with the greatly hydrated ammonia carried forcibly along
by the mass of gases.
In the 3rd operation the pure carbonic acid coming from soda calcining kilns
carries into the upper space of cylinder A. a part of the carbonate of ammonia, with
which it also unites in a gaseous condition. Lastly, in the fourth operation the
bi carbonisation of the liquids contained in the cylinder B is obtained by an
excess of pure carbonic acid, of which the surplus is also usefully employed in the
cylinder A.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, as communicated to me by my foreign correspondents,
I claim,―
First. The herein described process for manufacturing soda by the ammonia

page_text: method, wherein carbonic acid is caused to unite with ammonia or its volatile
compounds in a gaseous condition.
Second. The use of apparatus for the manufacture of soda by the ammonia
method, arranged and operating as herein described.
In witness whereof, I, the said John Imray, have hereunto set my hand and
seal, this Twelfth day of April, in the year of our Lord One thousand
eight hundred and eighty two.
JOHN IMRAY. (LS.)