IMPROVEMENTS IN THE MANUFACTURE OF CARBONATES OF SODA
Year: 1854

page_text: LETTERS PATENT to Theophile Schloesing, of Paris, in France, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF CARBONATES OF SODA."
Sealed the 22nd August 1854, and dated the 28th June 1854.
PROVISIONAL SPECIFICATION left by the said Theophile Schloesing at the
Office of the Commissioners of Patents, with his Petition, on the 28th
June 1854.
I, THEOPHILE SCHLOSING, of Paris, in France, do hereby declare the nature
of the Invention for "IMPROVEMENTS IN THE MANUFACTURE OF CARBONATES OF
SODA" to be as follows:-
This Invention consists in causing a solution of chloride of sodium to bo
placed in horizontal cylinders, in which are mechanical agitators, and into
these cylinders carbonic acid and ammoniacal gases are passed, by means of
which a precipitate of bi-carbonate of soda is produced. The excess of gas
which passes through the cylinders without being absorbed is caused to pas
over coke, moistened with solutions of chloride of calcium and hydrochloric
acid, by which it is retained.
The precipitated bi-carbonate of soda is separated from the containing liquid
by means of a centrifugal machine. The separated bi-carbonate of soda is
converted into the neutral carbonate by roasting. and the carbonic acid gas
which escapes is used to produce à further quantity of bi-carbonate, in the

page_text: manner already described. The roasting is effected in a retort, in which are
screw blades mounted on an axis, which cause the materials to travel from the
end at which they enter to the end at which they are discharged. The retort
is heated by means of the waste gases from a lime kiln, (where lime is obtained,
which is used in an after part of the process), and from this source also a
further supply of carbonic acid gas is obtained, to be used in the formation of
the bi-carbonate of soda. Ammonia is separated from the liquid from the
centrifugal machine by the addition of lime. From the same liquid carbonic
acid is separated by boiling, and goes to form more bi-carbonate, and chloride
of sodium is separated by evaporation.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Theophile Schloesing in the Great Seal Patent Office on the
27th December 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THEOPHILE
SCHLESING, of Paris, in France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of June, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Theophile Schloesing, Her special licence that I, the said Theophile
Schloesing, my executors, administrators, and assigns, or such others as I, the
said Theophile Schloesing, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF. CARBONATES OF SODA," upon the condition
(amongst others) that I, the said Theophile Schlæsing, by an instrument in
writing under my band and seal, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Theophile Schlosing, do, hereby declare
the nature of the said Invention, and in what manner the same is to be per-

page_text: formed to be particularly described and ascertained in and by the following
statement thereof (that is to say):—
This Invention consists in causing a solution of chloride of sodium to be
placed in horizontal cylinders in which are mechanical agitators, and into these
cylinders carbonic acid and ammoniacal gases are passed, by means of which
a precipitate of bi-carbonate of soda is produced. The excess of
passes through the cylinders without being absorbed is caused to pass over
coke, moistened with solutions of chloride of calcium and hydrochloric acid, by
which it is retained.
gas which
The precipitated bi-carbonate of soda is separated from the containing liquid
by means of a centrifugal machine. The separated bi-carbonate of soda is
converted into the neutral carbonate by roasting, and the carbonic acid gas
which escapes is used to produce a further quantity of bi-carbonate, in the
manner already described. The roasting is effected in a retort, in which are
screw blades mounted on an axis, which cause the materials to travel from the
end at which they enter to the end at which they are discharged. The retort
is heated by means of the waste gases from a lime kiln, (where lime is obtained,
which is used in an after part of the process,) and from this source also a fur-
ther supply of carbonic acid gas is obtained, to be used in the formation of the
bi-carbonate of soda. Ammonia is separated from the liquid from the centri-
fugal machine by the addition of lime. From the same liquid carbonic acid is
separated by boiling, and goes to form more bi-carbonate, and chloride of
sodium is separated by evaporation.
Having thus stated the nature of the said Invention, I will now proceed to
describe the manner in which the same is to be performed.
When carbonic acid gas is caused to pass through water containing a solu-
tion of chloride of sodium and ammonia, and when the operation is continued
till the water is unable to absorb any more carbonic acid gas, a precipitate of
bi-carbonate of soda is produced, which, when separated by filtration, washed,
and calcined, gives neutral carbonate of soda. I will at first state the different
operations of my process, and will explain them hereafter.
First operation. I cause salt water to absorb ammoniacal gas and carbonic
acid, the proportions being as follows:-For one hundred parts of water, thirty
or thirty-three parts of chloride of sodium; eight and a half or ten parts of
ammoniacal gas; the carbonic acid being used in excess.
Second operation.-The produced precipitate of bi-carbonate of soda is
separated from the containing liquid by means of a centrifugal machine.
Third operation. -The bi-carbonate of soda is roasted in a peculiar appa-
ratus, and the carbonic acid which escapes is collected and used, as herein-after

page_text: ends of which are supported in bearings p, p, p, p; they are driven by means
of pulleys q, q, and they carry inside the cylinders vertical discs (Figure 3), of
which the diameter is almost equal to that of the cylinders, and which are
provided with holes (Figures 5 and 6).. The discs in 'the cylinder M are made
of deal, and those in the cylinder N of galvanized iron. Their openings are
not placed opposite each other, so that the gases are obliged to follow a zig-zag
Bars of sheet iron t, t, t, t, (Figure 3,) strengthen the discs and con-
stantly agitate the liquid; at both ends of the cylinders the shafts pass through
stuffing boxes. When the work of the cylinders M and N is stopped, the
contents of M. are run through the tube S into a reservoir, then caustic
ammonia is immediately introduced into the cylinder to prevent the iron being
oxidised.
course.
:
By the process above described a very small quantity of ammonia is lost.
Very large absorbing surfaces are used in the cylinders M and N, and con-
sequently the gas is quickly absorbed, the liquids which the chemical reaction
heats are constantly cooled, and the work is not interrupted.
SECOND OPERATION.
The centrifugal apparatus, by means of which I separate the precipitate of
bi-carbonate of soda from the containing liquid, is similar to that used by sugar
refiners, and being well known it is not necessary to describe it. I shall only
remark, first, that the apparatus should be made of tinned copper, or other
material not acted upon by the liquid; second, that if pure carbonate of soda
is to be obtained, the precipitate must be washed in the apparatus with a
solution of bi-carbonate of soda, in the same manner that sugar refiners wash
their sugar.
THIRD OPERATION.
The roasting of the bi-carbonate of soda is effected in a horizontal cylinder
A, (Figure 7,) made of sheet iron, closed at both ends and placed over a fire,
the flame of which goes through a flue C, and through an upper flue C', and
comes out through the opening P made in the brickwork. D is an iron axis,
carrying. by means of iron rings e, c, four screw blades of sheet iron.f, f, f, ƒ.
Communicating with the cylinder is a tube M, provided with 'a cover, and
through which is introduced the bi-carbonate of soda; the saine cylinder is also
furnished with a tube N, through which escapes the gases produced by the
roasting, and a tube Q, through which the roasted carbonate of soda falls into
a box B of sheet iron. p, p, are the bearings of the axis D; q is a driving
pulley; c, c, c, c, are two iron tubes, fixed at their ends to the cylinder A, and
carrying at their other ends stuffing boxes.b, b, b, b. ; ·
1.
:

page_text: The bi-carbonate introduced through the tube M is caused to travel from
one end of the cylinder to the other by the screw blades. The gases and
vapours produced are carried by the tube N to a refrigerator full of cold
water, and afterwards into the cylinder by the tube c; the watery vapours are
condensed in the refrigerator, and the condensed water, which contains some
ammonia, is collected and used to dissolve the salt in the vat C, (Figures 1
and 2), or the ammonia is separated from it in the manner herein-after
described.
The cylinder A (Figure 7) may be heated by means of a furnace provided
with a grate, but I prefer to use the heat furnished by a lime kiln, herein-after
described.
F is a lime kiln, closed at the top by a cover, and the lower opening of
which is lateral, and closed by an iron door a, a. V is a ventilator, which
forces air into the kiln through the pipe T, and through the pipe S to the
chamber X, into which it throws enough air to change into carbonic acid the
carbonic oxide formed in the kiln. R is a valve which regulates the intro-
duction of air into the pipes T and S. The gases burnt in X, after having
heated the cylinder A, pass out at P, from whence they are carried by a pipe
into the cylinder N of Figure 2, in which the carbonic acid is absorbed by
the liquid.
These gases contain more carbonic acid than can be used, and consequently
their introduction into the cylinder N, Figure 2, is to be regulated. It is
also desirable that the part of those gases which is to enter into the cylinder
N should be cooled, and for that purpose I employ the following process:-
P (Figure 8) is the end of the tube coming from the opening P (Figure 7);
r is a cock which regulates the introduction of the gases into the pipe U.,
which allows the gases to escape into the open air and into the pipe T, which
carries part of the gases into a sheet iron cylinder R full of coke, con-
stantly moistened by cold water, brought by the pipe m; the cooled gases then
pass through the tube a, a, into a gasometer A, A, the weight of which is
regulated as required, from which the pipe b, b, conducts the gases into the
cylinder N (Figure 2).. The gasometer acts by means of a rope c, c, on the
valve, and the water brought by the pipe m into the cylinder R escapes from
the same through a tube o, ending in D.

page_text: First, the manner of producing bi-carbonate of soda in the cylinders M, N,
Figure 1, and the arrangement of apparatus for that purpose, as described.
Second, the use of the centrifugal apparatus to separate and wash the bi-
carbonate of soda, as described.
Third, the manner of roasting the bi-carbonate of soda, and the arrange-
ment of apparatus for that purpose. :
Fourth, the use of a lime kiln for supplying carbonic acid gas and heating
the retort, as herein described.
And, fifth, the operation by which the carbonic acid is separated from the
liquid, and the apparatus used for that purpose.
In witness whereof, I, the said Theophile Schloesing, have hereunto set
my hand and seal. this Twenty-second day of December, in the year of
our Lord One thousand eight hundred and fifty-four.
Witness,
T. BASSET,
2, Rue Drouot.
TH. SCHLESING. (L.S.)