IMPROVEMENTS IN APPARATUS TO BE EMPLOYED IN THE PRO- DUCTION OF CARBONATE AND BICARBONATE OF SODA FROM SULPHATE OF SODA OR FROM CHLORIDE OF SODIUM
Year: 1884

page_text: PROVARIONAL DIECIFICATION.
We HOLBROOK GASKELL of Woolton Wood in the County of Lancaster
Manufacturing Chemist and FERDINAND HURTER Ph: D. of Widnes in the
County of Lancaster Analytical Chemist do hereby declare the nature of said
Invention for "IMPROVEMENTS IN APPARATUS TO BE EMPLOYED IN THE PRO-
DUCTION OF CARBONATE AND BICARBONATE OF SODA FROM SULPHATE OF SODA
OR FROM CHLORIDE OF SODIUM" to be as follows:-
This Invention relates to an apparatus to be employed in the production of
Bicarbonate of Soda from Sulphate of Soda or from Chloride of Sodium and is
especially adapted for use in carrying out the process described in the Specification
of Letters Patent No 5712 granted to Eustace Carey and Ferdinand Hurter as of the
11th December 1883.
According to our present Invention the apparatus which we employ for preparing
the solution of Sulphate of soda consists of a wrought iron dissolving vessel placed
at a sufficiently high level to allow the solution to flow by gravity to any of the
other parts of the apparatus in which it may be wanted.
This vessel is filled with water or with weak solutions of Sulphate of Soda. The
sulphate of Soda which is to be dissolved is charged in any convenient manner into
a basket or cage in the said vessel near the top thereof and steam is admitted and
an agitator provided in the said vessel is set in motion by suitable gearing in
order to hasten the solution and mix it well with the Carbonate of Soda used for
Deutralising.
+
When the solution is sufficiently saturated and has a strength of about 55° to 60°
Twaddell at or near the boiling point and has been rendered properly alkaline it is
run off by a suitable outlet valve into reservoirs where the solution is allowed to
settle and to rest until it is sufficiently cool (say till it reaches 100° Fahrenheit).
The solution is then withdrawn which may be conveniently effected by means of
swivel syphons arranged at the side of each reservoir and is conveyed to the
saturators by means of a suitable pipe.
The sediment which deposits at the bottom of the reservoirs can be withdrawn
by valves and is washed in a filter press or any other suitable apparatus or it may

page_text: be washed in the reservoirs but it is preferable to wash it elsewhere. The dilute
solution obtained by washing this sediment is again used for dissolving sulphate
of Soda in the dissolving vessel.
The apparatus for treating the sulphate of Soda solution with Ammonia and
Carbonic Acid consists of a series of wrought iron carbonating vessels capable of
withstanding a working pressure of at least 30 to 40lbs per square inch. Each of
these vessels is provided with a manhole for cleaning and small taps to permit
samples of the contents to be withdrawn. The said carbonating vessels are sup-
ported at different levels on suitable frame-work so that the solution may flow from
one vessel to the next below it by gravity and the difference of level between any
two of these vessels must be equal at least to the depth of the liquid within the
vessel. One or more of the carbonating vessels is or are arranged at a lower
level than the others. We use preferably two such vessels at a low level which
work alternately while the higher carbonating vessels work continuously. All of
the carbonating vessels contain ammoniacal solution of Sulphate of Soda which
gradually descends from the highest vessel to the lowest and in descending meets a
current of carbonic acid gas which is propelled by a pump and enters the system
of vessels through a suitable pipe provided with valves which permit the gas to pass
into the lower carbonating vessel or vessels as required. The Gas then passes down
to the bottom of the said vessel or vessels where it is distributed by perforated
pipes or by a rose. It ascends through the solution and leaves the said vessel or
vessels by a suitable outlet pipe provided with valves and enters the first of the
higher carbonating vessels. At the bottom of this vessel the gas is again dis-
tributed by a perforated pipe or rose and in a similar manner passes to the. next
carbonating vessel and then similarly to the remaining carbonating vessel or vessels.
Most of the Carbonic Acid is now absorbed but the gas carries with it a certain
amount of ammonia. In order to absorb this ammonia the Gas is next passed by
a suitable pipe through absorbing vessels which are arranged the last at a higher
level than the first and which may be in every respect similar to the other vessels
but which contain a solution of Sulphate of Soda obtained from the reservoirs
herein before mentioned. The gas passes through these absorbing vessels and thus
is washed by the solution contained therein and leaves the last of the vessels by a
suitable pipe and may be deprived of the last traces of ammonia by being passed
through a coke scrubber or other suitable apparatus such as is used in Gas
Works in which apparatus the ammonia is absorbed either by water or by
sulphuric acid.
The Sulphate of Soda Solution which serves to wash the Gas flows from tho
herein before mentioned reservoirs into the last of the absorbing vessels by the exit
pipe from the said reservoirs and flows from the said vessel to the first or lowermost
absorbing vessel. By passing through these absorbing vessels the solution is partially
charged with ammonia or carbonate of ammonia but the quantity of ammonia thus
brought into solution is not sufficient and more must be added. For this purpose a
sufficient number (say two) of auxiliary wroughtiron absorbing vessels is provided
each having a jacket and agitators. The jacket serves to prevent the contents from
over heating by allowing cold water to circulate between the jacket and the vessel.
These auxiliary vessels are connected with the lowermost of the absorbing vessels
by pipes and stop cocks in such manner that the said auxiliary vessels may be filled
by opening the said stop cocks. When one of the said auxiliary vessels is filled the
corresponding cock is shut and ammonia gas is admitted to the said vessel which
gas may be evolved in a "Coffey" still or other like apparatus and brought to
the vessel by a pipe provided with stop cocks one for each vessel. When the
solution is rendered sufficiently ammoniacal (which can be ascertained by testing a
sample withdrawn by a sampling tap provided for the purpose) it is pumped
through a pipe into the highest of the carbonating vessels wherein the carbonating
begins. The liquid then gradually descends from vessel to vessel of the carbonating
series until it arrives at one or other of the lowermost of the said carbonating
vessels where the carbonating is completed. The absorption of the carbonic acid

page_text: causes the solution to become warm. This is of no great consequence in the highest
carbonating vessels but in the lower of the said vessels the temperature ought not
to rise much above 100° Fahrenheit otherwise the pressures necessary for the process
become objectionably high. In order to be able to regulate the temperature we
place between every two of the carbonating vessels a trough containing or having
a circulation of cold water into which trough we place a coil of pipes through which
the solution passes as it flows from one vessel to the next and is thus cooled to the
réquisite temperature. After the solution has passed through the higher series of
carbonating vessels it is made to flow into an empty vessel at the lowest level
whilst the gas is made to pass through one 'which is full. When the latter one is
completely carbonated and the other one filled the gas is caused to pass through
the one just filled by operating the valves. The contents of the other of the vessels
when carbonated are emptied by a suitable outlet. The valves of the outlet pipes
are open except when it is desired to clean out one of the lowermost vessels.
The contents of these Towermost carbonating vessels when completely carbonated
consist of a solution of sulphate of ammonia, a little sulphate of soda and bicar-
bonate of ammonia which solution holds in suspension bicarbonate of soda as a fine
crystalline precipitate. This liquid is allowed to cool and the bicarbonate of soda
is separated by a suitable filter.
The bicarbonate of Soda is then heated to drive out the ammonia and the one
half of the carbonic acid which it contains the ammonia is absorbed in water
and the carbonic acid passed again into the system by means of a pump.
Although we have mentioned wrought iron as the material for the construction
of the vessels we of course can use any other material that may be suitable for the
purpose.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said Holbrook Gaskell and
Ferdinand Hurter.

page_text: "
COMPLETE SPECIFICATION.
We HOLBROOK GASKELL of Woolton Wood in the County of Lancaster
Manufacturing Chemist and FERDINAND HURTER Ph: D. of Widnes in the County.
of Lancaster Analytical Chemist do hereby declare the nature of this invention
for IMPROVEMENTS IN APPARATUS TO BE EMPLOYED IN THE PRODUCTION OF
CARBONATE AND BICARBONATE OF SODA FROM SULPHATE OF SODA OR FROM
CHLORIDE OF SODIUM" and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This Invention relates to an apparatus to be employed in the production of
Bicarbonate of Soda from Sulphate of Soda or from Chloride of Sodium and is
especially adapted for use in carrying out the process described in the Specification
of Letters Patent No 5712 granted to Eustace Carey and Ferdinand Hurter as of
the 11th December 1883.
We will describe our present Invention with reference to the accompanying
drawings. The apparatus which we provide according to our said Invention for
preparing the solution of Sulphate of Soda is illustrated in Figure 1. It consists of
a wrought iron dissolving vessel A placed at a sufficiently high level to allow the
solution to flow by gravity to any of the other parts of the apparatus in which it
may be wanted.
This vessel A is filled with water or with weak solutions of sulphate of soda.
The sulphate of soda which is to be dissolved is charged in any convenient manner
into a basket or cage B in the said vessel near the top thereof and steam is
admitted, and an agitator C, provided in the said. vessel, is set in motion by
suitable gearing such for example as is shewn at D, in order to hasten the solution-
and mix it well with the carbonate of soda used for neutralizing.
When the solution is sufficiently saturated and has a strength of about 55°
to 60° Twaddell at or near the boiling point and has been rendered properly
alkaline it is run off by an outlet valve at E into reservoirs F F where the solution
is allowed to settle and to rest until it is sufficiently cool (say till it reaches
100° Fahrenheit).
The solution is then withdrawn which may be conveniently effected by means
of swivel syphons G arranged at the side of each reservoir and the said solution is
conveyed to the saturators by means of a pipe as at H.
The sediment which deposits at the bottom of the reservoirs F can be withdrawn
by valves I and is washed in a filter press or any other suitable apparatus or it
may be washed in the reservoirs but it is preferable to wash it elsewhere The
dilute solution obtained by washing this sediment is again used for dissolving
sulpbate of soda in the dissolving vessel A.
The sulphate of soda may be obtained in any suitable way. It may for example
be the sulphate of soda obtained as a bye product from Chloride of sodium in the
manufacture of hydrochloric acid.

page_text: The apparatus arranged according to our Invention for treating the sulphate of
soda solution with ammonia and carbonic acid is represented in elevation and plan
in figures 2 and 3. It consists of a series of wrought iron carbonating vessels
lettered V capable of withstanding a working pressure of at least 30 lbs to 40 lbs
per square inch. Each of these vessels is provided with a man-hole for cleaning,
and small taps to permit samples of the contents to be withdrawn.
The said carbonating vessels are supported at different levels on suitable frame
work so that the solution may flow from one vessel to the next below it by gravity
and the difference of level between any two of these vessels must be equal at least
to the depth of the liquid within the vessel. We use preferably two of the
carbonating vessels arranged at a lower level as shewn at V1 V₁, which vessels
work alternately while the higher carbonating vessels V2 V3 V work continuously.
All of the carbonating vessels V₁ to V contain ammoniacal solution of sulphate of
soda which gradually descends from the highest vessel V to the lowest V₁ and in
descending meets a current of carbonic acid gas which is propelled by a pump or
other suitable forcing means, and enters the system of vessels through a pipe L
provided with valves which permit the gas to pass into the lower carbonating
vessel or vessels V₁ as required. The gas then passes down to the bottom of the
Baid vessel or vessels V where it is distributed by perforated pipes or by a rose.
It ascends through the solution and leaves the said vessel or either of the vessels
by an outlet pipe L' provided with a valve and enters the first vessel Vs of the
higher carbonating vessels. At the bottom of this vessel V the gas is again
distributed by a perforated pipe or rose and in a similar manner passes to the next
carbonating vessel V³ by the pipe L' and then similarly by the pipe L³ to the
remaining carbonating vessel V, and so on, if there be a greater number of vessels
than we have shewn, for we do not limit ourselves to the number shewn. Most
of the carbonic acid is now absorbed but the gas carries with it a certain amount
of ammonia.
In order to absorb this ammonia the gas is next passed by means of pipes L* L*
into and through absorbing vessels V5 Vo which are arranged, the last Ve at a
higher level than the first V, and which may be in every respect similar to the
other vessels V¹ to V, but which contain a solution of sulphate of soda obtained
from the reservoirs herein before mentioned. The gas passes through these
absorbing vessels V5 V6 and thus is washed by the solution contained therein and
leaves the last of the vessels V by a suitable pipe and may be deprived of the last
traces of ammonia by being passed through a coke scrubber or other suitable
apparatus (not shewn in the drawing), such as is used in Gas Works, in which
apparatus the ammonia is absorbed either by water or by sulphuric acid.
The sulphate of soda solution which serves to wash the gas, flows from the
hereinbefore mentioned reservoirs (F figure 1) into the last of the absorbing
vessels V6 by the pipe H and flows from the said vessel into the first or lowermost
absorbing vessel Vs.
We do not limit ourselves to the number of absorbing vessels sbewn.
By passing through these absorbing vessels the solution is partially charged with
ammonia or carbonate of ammonia but the quantity of ammonia thus brought into
solution is not sufficient and more must be added For this purpose there is
provided a sufficient number (say two), as shewn at M¹ M², of auxiliary wrought
iron absorbing vessels, each having a jacket and agitators Between the vessel and
jacket cold water can be caused to circulate, to prevent the contents of the vessels
from over heating-These auxiliary vessels are connected with the lowermost
vessel V of the absorbing vessels by pipes and stop cocks m in such manner that
the said auxiliary vessels may be filled by opening the said stop cocks m and the
air escape valves q-When one of the said auxiliary vessels is filled the corre-
sponding cock is shut and ammonia gas is admitted to the said vessel, which gas
may be evolved in a "Coffey" still, or other like apparatus, and brought to the
vessel by a pipe K provided with stop cocks k, one for each vessel-When the
solution is rendered sufficiently ammoniacal (which can be ascertained by testing a

page_text: sample withdrawn by a sampling tap provided for the purpose) it is pumped
through a pipe N into the highest of the carbonating vessels V4 wherein the
carbonating begins The liquid then gradually descends from vessel to vessel of
the carbonating series until it arrives at one or other of the lowermost of the said
carbonating vessels V₁ where the carbonating is completed The absorption of the
carbonic acid causes the Solution to become warm This is of no great consequence
in the highest carbonating vessels but in the lower of the said vessels the
temperature ought not to rise much above One hundred degrees Fahrenheit
otherwise the pressures necessary for the process become objectionably high-In
order to be able to regulate the temperature we place between every two of the
carbonating vessels a trough P, through which is passed cold water, and into these
troughs P we place a coil of pipes through which the solution passes as it flows from
one vessel to the next and is thus cooled to the requisite temperature-After the
solution has passed through the higher series of carbonating vessels it is made to
flow into an empty vessel V1 at the lowest level whilst the gas is made to pass
through one V which is full-When the contents of the latter are completely
'carbonated and the other is filled, the gas is caused to pass through the one just
filled by operating the valves The contents of the other of the vessels when
carbonated are emptied by a suitable outlet for instance by the cock O. The
valves of the outlet pipes are open, except when it is desired to clean out one of
the lowermost vessels.
The contents of these lowermost carbonating vessels, when completely carbonated,
consist of a solution of sulphate of ammonia, a little sulphate of soda and bicar-
bonate of ammonia, which solution holds in suspension bicarbonate of Soda as a
fine crystalline precipitate-This liquid is allowed to cool and the bicarbonate of
Soda is separated by a suitable filter.
The bicarbonate of Soda is then heated to drive out the ammonia and the one
half of the carbonic, acid which it contains, the ammonia is absorbed in water, and
the carbonic acid passed again into the system by means of a pump.
Although we mention wrought iron as a suitable material for the construction
of the vessels, we of course can use any other material that may be suitable for
the purpose.
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 claim is
The arrangement and combination of parts constituting the apparatus for
operation, substantially as and for the purpose hereinbefore described and illustrated
in figures 1, 2 and 3 of the accompanying drawings.