APPARATUS BY MEANS OF WHICH THE FORMATION OF CARBONATES OF SODA BY DIRECT COMBIN PRACTICALLY AVAILABLE FOR MANUFACTURING PURPOSES
Year: 1863

page_text: LETTERS PATENT to Ernest Solvay, of Brussels, in the Kingdom of
Belgium, Chemist, for the Invention of "APPARATUS BY MEANS OF WHICH
THE FORMATION OF CARBONATES OF SODA BY DIRECT COMBINATION IS RENDERED
Sealed the 20th May 1864, and dated the 11th December 1863.
PROVISIONAL SPECIFICATION left by the said Ernest Solvay at the
Office of the Commissioners of Patents, with his Petition, on the
11th December 1863.
I, ERNEST SOLVAY, of Brussels, in the Kingdom of Belgium, Chemist,
do hereby declare the nature of the said Invention for
Invention for "APPARATUS BY
MEANS OF WHICH THE FORMATION OF CARBONATES OF SODA BY DIRECT COMBINA-
TION IS RENDERED PRACTICALLY AVAILABLE FOR MANUFACTURING PURPOSES," to be
as follows:
It is well known that carbonate of soda may be manufactured direct by
bringing into the presence of each other either successively or simultaneously
carbonic acid, ammonia, and common salt.
The object of this Invention is to effect this in a more simple and expe-
ditious manner than heretofore. For this purpose a series of apparatus are
employed by which the successive operations are automatically performed, it
being only necessary to supply them with the requisite ingredients.
The first portion of the apparatus consists of a vessel containing common
salt, through which a stream of water (regulated by a float valve) is made to
flow from a supply pipe; by this means the water will dissolve and take up the

page_text: requisite quantity of salt. The brine thus produced flows into another vessel,
chamber, or apparatus, for the purpose of absorbing the necessary proportion
of ammonia. This apparatus consists of a vessel divided into three com-
partments which are made to communicate with each other.
The brine
flows direct from the first apparatus into the second compartment of this
vessel, from whence it flows back into the first compartment for the purpose
of absorbing the requisite quantity of ammonia, which is supplied to this
The
compartment by means of a pipe conveniently placed for the purpose.
brine as it becomes charged with its proper quantity of ammonia rises in the
first compartment and flows over through a syphon into the third com-
partment, in which is a worm for cooling the hot liquid. Should the brine be
too strong, and thereby cause a deposit of salt, it may be diluted with water
by means of a pipe in the first compartment. From this apparatus the
brine, now containing ammonia, flows into another, where it becomes saturated
with carbonic acid by means of a force pump. If this gas be produced in the
ordinary, (which is preferred), viz., by the calcination of calcareous matters,
the gas should be passed through a cooling and washing apparatus. This
apparatus consists of a vessel for containing the washing liquid provided with
entrance and exit pipes for the gas, which is pumped in, and after passing
through the washing liquid makes its exit at the opposite side, a waste pipe
being provided to prevent overflow of the liquid. The apparatus for impreg
nating the liquor with carbonic acid consists of an oblong vessel divided into
three parts, the upper one of which is called the washer and the lower ones the
saturators. These compartments, which communicate with each other by
means of pipes and valves, are provided with horizontal partitions on which
are laid perforated false bottoms having their ends bent or arched for that
purpose.
The ammoniacal brine on flowing into this apparatus first fills the inter-
mediate saturator, then passes up the connecting pipe into the upper compart-
ment or washer, and then again descends through another connecting pipe into
the lower compartment or supersaturator, whence it may be drawn off by
means of a cock. The gas with which the liquid is to be saturated is forced
in (at a pressure of at least half an atmosphere) at the bottom of the vessel
and passes up through the liquid and along the partitions and through the
perforated false bottoms, valves opening upwards being provided in the
partitions to prevent the return of the gas. The gas on leaving the apparatus
at the top passes through a washing apparatus containing water, either pure
or charged with acid, for the purpose of depriving it of any ammonia..
..
On leaving this apparatus the liquor no longer contains common salt, com-

page_text: mercially speaking, the reaction having converted it into bi-carbonate of soda
in suspension and hydrochlorate of ammonia in solution.
The liquor thus obtained may now be decanted in the usual manner, and it
now only remains to deprive it of the ammonia together with a small portion of
carbonic acid which it may contain, that is to say, the ammoniacal gas produced
is mixed with a small quantity of carbonate of ammonia. For this purpose the
liquor is fed into a distilling apparatus consisting of an oblong pipe or vessel
which is broader and higher at its middle than at the sides, and is surrounded
by a water jacket, that being heated by furnaces at one end acts as a steam
generator, and the other being filled with cold water acts as a refrigerator to the
liquid and gas inside; slaked lime is supplied to the liquor in the centre of the
apparatus by a vertical pipe and beater shaft, and this liquor being raised to a
bigh temperature by the surrounding hot water or steam jacket, the ammonia-
cal gas will be disengaged, and passing along the apparatus will be deprived
of its humidity, carrying off at the same time the carbonate of ammonia at that
side of the apparatus where there is no lime to decompose it, and finally,
passing through a pipe above, it enters the pipe where ammonia is required
to be supplied to the brine.
It will be understood that the greater part of the operation being conducted
in closed vessels, the loss of the ammonia by evaporation will to a great extent
be prevented.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Ernest Solvay in the Great Seal Patent Office ou the 11th
June 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ERNEST
SOLVAY, of Brussels, in the Kingdom of Belgium, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her, Letters
Patent, bearing date the Eleventh day of December, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Ernest Solvay, Her special license that I, the said Ernest
Solvay, my executors, administrators, and assigns, or such others as I,
the said Ernest Solvay, 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

page_text: Ireland, the Channel Islands, and Isle of Man, an Invention for "APPARATUS
BY MEANS OF WHICH THE FORMATION OF CARBONATES OF SODA BY DIRECT COM-
BINATION IS RENDERED PRACTICALLY AVAILABLE FOR MANUFACTURING PURPOSES,"
upon the condition (amongst others) that I, the said Ernest Solvay, by
an instrument in writing under my hand 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 Ernest Solvay, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed and to the
letters and figures marked thereon (that is to say):-
Carbonate of soda may be manufactured direct by bringing into the
presence of each other, either successively or simultaneously, carbonic acid,
ammonia, and common salt, but all attempts to bring the reaction thus
produced into practice so as to work it commercially with advantage have
hitherto failed.
This result is, however, obtained by the employment of the apparatus
forming the subject of the present Invention, and which will be under-
stood by the following description, reference being had to the accompanying
Drawing.
Fig. 1 being a vertical section of the apparatus, and Fig. 1° a portion
detached in plan view. The first portion of the apparatus which serves for
the dissolution of the salt and the introduction and absorption of the
ammonia consists of a vessel a, b, c, d, (which is in this instance represented
of a square form,) divided by partitions e, f, g, h, i, j. Into this vessel salt is
thrown, and at one of its extremities is a reservoir R, of any convenient form,
and divided in the middle by a partition, which is of a height equal to that
at which it is desired to maintain the liquid in the preceding vessel, that is to
say, a little lower than the partitions. A stream of water in excess falls
constantly into this reservoir, and the surplus water passes over the partition,
and escapes through the pipe t, so as to be employed for other purposes.
By this arrangement one part of this reservoir always contains water at the
same level, which part communicates directly below with the dissolving vessel,
in which an invariable level is consequently always maintained. This water
passes through all the divisions of the vessel, and takes up the salt therein,
and does not arrive at the other end of the vessel at 7 until it is completely

page_text: saturated, that is to say, until it marks twenty-five degrees on the salinometer.
This density being somewhat too great, it is reduced to twenty-three or twenty-
four degrees by the addition of a certain quantity of water, which constantly
flows into it at u, the supply being regulated by a cock. The last compart-
ment of the solution vessel is wider than the other, and is arranged in such a
manner as to receive a filter a', 6', formed of several coarse cloths for
arresting the impurities contained in the liquid. This compartment is repre-
sented in section at Fig. 1. The dissolving vessel communicates at / with
a second vessel A (Fig. 2) by means of a pipe of sufficient length to make
several turns or bends horizontally in the lower part of the vessel A, where
it terminates in a cock at f. The saline solution therefore fills it up to the
level it occupies in the preceding vessel. The liquor makes its escape from
this vessel through a pipe C, the extremity of which may be raised or lowered
at pleasure. This vessel A is provided with a false bottom 6 pierced with
small holes, underneath which a pipe supplies the ammonia, which passes
through the perforations in the false bottom, and is immediately dissolved in
the liquid, which becomes the lighter the more ammonia it absorbs.
Now as
the liquor in the solution vessels remains always at the same level and
density, the pressure on that side is always equal. To counterbalance it the
liquid contained in the vessel A must rise as it becomes lighter. The beight
at which it makes its exit is regulated in such a manner that when its density,
which was at first from twenty-three to twenty-four degrees, shall be reduced
in consequence of the absorption of ammonia to about fifteen or sixteen
degrees it will rise and run over.
It is evident that when once the apparatus is set to work it will work
without intermission and with regularity, the ammoniacal brine being con-
tinuously replaced by the supply of fresh brine from below in equivalent
quantity. From the vessel A the ammoniacal liquor heated by the reaction
enters another vessel B, where it is cooled by a worm D through which a
stream of cold water passes and makes its escape below at e.
By the novel application of the principle of difference in specific gravity
between the pure and ammoniacal brine, the liquid will not leave the vessel B
until it has taken up exactly the necessary quantity of ammonia, and by this
arrangement the absorption will continue for any length of time without
its being necessary to attend to the apparatus or watch the process. It
is clear that the application of this principle may be carried into effect in
various ways, for example, by the employment of floats, syphons, or other
mechanical equivalents.
I therefore claim as my Invention the application of this principle of

page_text: difference of density in the liquids whereby the ammoniacal liquid will, by its
difference of specific gravity or density, become separated from the liquid
which is not saturated with ammonia,
Two openings r, s, are made in the covers of the vessels A and B, to allow
of access to the exit pipe and also to the interior of the vessels. If the
ammoniacal gas be mixed with some portions of inert insalubrious gases, these
gases will rise to the upper part of the apparatus and escape through a
pipe t, arranged for that purpose, into the apparatus shewn at Fig. 3, where
it receives the carbonic acid, which may be produced by any known means,
such as the combustion of charcoal or the calcination or decomposition of
calcareous substances. If produced by the calcination of calcareous sub-
stances, which is the method ordinarily practised and employed by pre-
ference, the carbonic acid gas is to be passed through a washer and cooler
before entering the pump by which it is supplied to the apparatus. This
washer and cooler (which is shewn at Fig. 5) consists of a vessel A of any
convenient form, provided with a false bottom perforated with small holes,
underneath which the gas is forced through the pipe b by the sucking action
of the pump and passes in a state of division through the perforations in the
false bottom and up through the water contained in the vessel, and thence
passes in a cold state through the exit pipe c to the pump. The liquid con-
stantly supplies itself to the vessel through a pipe D and flows off through a
waste pipe e below into a small vessel f.
The most important point in the manufacture is to obtain complete reaction,
that is to say, the complete transformation of the soda of the salt into a car-
bonate. For this purpose the apparatus shewn at Fig. 3 is employed. It
consists of a vessel a, b, c, d, divided by horizontal partitions set one above
another, and above each of which are false bottoms e, f, g, h, i, j, perforated
with small holes, the total surface of which shall be calculated so as to be a
little more than equivalent to the section of the pipe which supplies the car-
bonic acid. The false bottoms (shewn in transverse section at Fig. 6) are
simply set upon the partitions, and are curved or bent at their ends and sides
in order to leave room for the circulation of the gas. Their sides are also
notched or serrated in order to allow of the passage of the gas in case of an
accidental obstruction of the holes. The length of the vessel much exceeds
its width, as will be seen by the partial plan view A, B, taken in the line a, b,
of Fig. 3. The apparatus is divided in the direction of its height into three
parts, which only communicate with each other by means of valves k, l, and
pipes m, n, o, p. The upper part is called the washer and the lower parts the
saturators.

page_text: The operation of the apparatus is as follows:-The liquor is supplied
through the pipe q leading from the ammoniacal brine vessel B, Fig. 2. The
vessels being closed of themselves, the liquor completely fills first the inter-
mediate part or saturator, ascends through the pipe p, o, into the upper part or
washer, and redescends afterwards through the pipe m, n, into the lower part
or saturator, whence it flows off through the cock at r. The carbonic acid
follows a different course; it enters below through the pipes and simply passes
upwards through the apparatus opening the valves in its passage and passing
through the perforations in the false bottoms; and as the carbonic acid has to
force its way through a high mass of liquid, it must be forced into the apparatus
at a minimum pressure of half an atmosphere. Pressure is certainly a
powerful means of assisting absorption, but it alone would be insufficient, for
which reason the following conditions are added, and which are fulfilled by the
employment of this apparatus, viz:-First, a long passage of the gas through
the liquid; it may be increased to any extent, and extends over one hundred
yards in this apparatus. Second, a constant division of the gas by its passage
through the perforated plates into an infinite number of bubbles, which reunite
and are again divided at the following compartment. The surface of contact
is thus caused to be of great extent. Third, passage of the liquid and the gas
in different directions throughout the apparatus, as is the case in all operations
in which the absorption of a gas by a liquid is required. Fourth, the appa-
ratus is always completely full, so that the gases may be held in the liquid.
Fifth, cooling of the apparatus by any convenient means, but more especially
by the employment of worms inside, through which cold water passes.
It will be easily understood that the combination of means so powerful
must produce a complete saturation of carbonic acid, at any rate, in the lower
compartments of the apparatus, where the gas arrives in all its intensity and
greatest purity upon liquor which it has already impregnated in the upper
compartments.
My apparatus was not originally divided into three distinct parts, as above
described, it was of somewhat less extent, and had free communication from
top to bottom without either valves for the gas or pipes for the liquid, which
flowed down from one partition to another; the carbonic acid, on the contrary,
followed the present course, but without having any valves to pass through.
Arranged in this manner the apparatus did not answer, the want of reaction
and the quantity of gas which was disengaged with the escaping gas were
sufficiently great to occasion me to try with the liquor following the same
course as the gas. The result of this trial was superior to what was
anticipated; the two defects above mentioned disappeared, but the apparatus
"L

page_text: became insufficient for producing all the result which was anticipated from it.
This fact led me to observe that the reaction was only incomplete before
because the ammonia was wanting in the lower parts of the apparatus. Not-
withstanding the very favorable conditions of this latter, in which by the
previous absorption of ammonia and the filling of the vessel ammonia floating
upon the liquid is avoided, the volatility of this gas caused a perceptible
quantity of it to be carried off by the current of inert gases which are forced
into the apparatus with the carbonic acid. This carrying off of the ammonia
took place especially in the upper parts where it was very abundant in the
volatile state, so that the liquid would only descend if it did not contain
the quantity of ammonia necessary for complete reaction. The observation
of these facts led me to adopt the present arrangement, which entirely does
away with the two evils first mentioned, vizt,, want of reaction and disengage-
ment of ammonia with the escaping gas, and also that caused by reversing the
current of liquid, viz., a deficiency in the product. In fact, the liquid, which
now supplies the upper part of the apparatus comes from the underneath
portion of the intermediate part of the apparatus or saturator before proceeding
to the washer; it has therefore already been submitted to the prolonged and
intense action of the carbonic acid, so that it no longer contains any free
ammonia capable of being carried off by the gas, but on the contrary it is
ready to take up any ammonia, and this is really the office it performs,
depriving these gases of any ammonia they may have carried off at the
highest part of the saturator. On leaving the apparatus the gases do not in
general contain any more ammonia. In order to avoid loss or waste the
gases are caused to pass through a washer (X, Y, Fig. 3) containing pure
water. This washer is similar to one of the compartments of the principal
apparatus; the water enters through a small pipe at X and makes its escape
at Y, the gas escaping through the pipe Z. With regard to the liquid, it
passes from the upper part of the apparatus or washer into the lower part or
saturator, where it first receives the carbonic acid, which is pumped in, and
where the reaction takes place in the most efficient manner. On leaving this
the liquid no longer contains common salt, commercially speaking, the
reaction is there complete, and gives out bi-carbonate of soda in suspension
and hydrochlorate of ammonia in solution.
In order to clean the apparatus from time to time the following means are
employed: Having completely emptied the apparatus it is to be filled with
clean water, which is afterwards heated to a high temperature by means of a jet
of steam passing through a pipe adapted for that purpose at the lower part of
the
apparatus. The cold water worms may also be made to receive steam for

page_text: this purpose, and by this means the liquid mass may be heated to a high
temperature very quickly. The crusts and bi-carbonate deposited which
remain are immediately dissolved, and the ammonia which still remains will
be disengaged at top and mixed with a large quantity of carbonic acid ; the
jet is directed into the water washer, where the ammonia is taken up, the
carbonic acid escaping outside. When the production of ammonia has ceased
the liquor is drawn off from the apparatus into another vessel; it contains
soda salt and common salt, which may be extracted from it by means of a
steam worm. By this means the cleaning operation is very expeditiously
performed. It is, however, very rarely necessary, in consequence of the
conformation of the apparatus. The side a, d, of the apparatus is bolted to
the other part; it may, therefore, be readily removed when access is required
to the interior. The valves are formed of a disc considerably larger. than the
opening, carrying one or more rods to guide them and prevent them from
getting out of place above. They close by their own weight when the gas is
not passing, and only open to the extent necessary for the passage of the gas.
Instead of the valves a bent or syphon pipe might be employed, which before
communicating from one part to another should rise to a certain height (a
little higher than the apparatus itself), so that the gas only should. pass
through it, as the liquor could never reach the top of the syphon. This
arrangement has, however, been found less simple than the valves, and there-
fore not necessary.
The industrial results of the above-described apparatus will be easily
understood.
First. Complete reaction is obtained and the object effected at once, which
prevents the necessity for costly operations, and also for again operating upon
matters which have been imperfectly acted upon.
Second. The absence of mechanical agents in the interior obviates the
necessity of having openings for gearing, for communicating motion to them,
and the trouble and expense of closing those openings, also the loss of
ammonia, the escape of which through these openings could not be avoided,
whereas in the present apparatus the operation is conducted in vessels which
are entirely closed. The necessity for keeping working parts in order is also
avoided, and consequently the necessity for stopping the operation when they
get out of order is obviated.
Third. The arrangement of the apparatus causes the reaction to be self-
acting by the simple flow of the liquor, as in the two previous apparatus
shewn at Figures 1 and 2, and thus by regulating the flow the liquid may by
experience be made to run out continuously with complete reaction:

page_text: Fourth. The vessels being constantly full will prevent the deposit of crust,
which is produced especially in those parts to which the liquor has little or no
access. This is a very important point in which the result has been successful
beyond expectation.
Fifth. The washing of the gas in the liquid itself already saturated, in order
to collect the ammonia and convey it where it is required, renders washing
afterwards unnecessary.
Sixth. The numerous and narrow communications, together with the absence
of all violent movement, cause the liquor to advance in the required order.
Seventh. The jet of steam, the introduction of water, and the facility of
taking the apparatus to pieces, will effectually prevent all causes of obstruction
or facilitate their removal.
Eighth. The liquor on coming from the apparatus being completely
saturated with carbonic acid will no longer possess the slightest ammoniacal
odor, and will, if necessary, bear contact with the air on being poured out
without losing any of that valuable substance.
It will be readily understood that the form or proportion of the apparatus
may be modified without departing from the principle or losing any of the
advantages of my Invention; for instance, there may be as many cases as
compartments; the division of the gas may be effected otherwise than by
perforated plates, for instance, by means of pipes having "roses" at their ends
or by spongy masses, such as coke; the form of the compartments may be
varied, so that they shall be dissimilar, &c. The liquor as it comes from the
For the
apparatus may be decanted by any suitable and well-known means.
purpose of reducing the bi-carbonate of soda thus produced into neutral
carbonate, and utilizing the carbonic acid disengaged, the apparatus shewn at
Fig. 7 in sectional elevation, and in cross section at Fig. 8, is employed. It
consists of three iron tubes A, B, C, set one above the other, and communi-
cating alternately with each other at their opposite ends a, b. Each of these
tubes is provided with an axle furnished with helicoidal beaters which traverse
the bottom of each tube where it is provided with a toothed wheel; these
three toothed wheels c, d, e, take into and drive each other, and are set in
motion by a pinion f mounted upon a shaft worked by means of a pulley g.
By this arrangement each shaft is alternately worked in an opposite direction.
The
apparatus is charged with damp bi-carbonate of soda by a hopper E which
is always kept full and supplies it continuously and when required. This salt
is continually stirred and moved forward by the beaters, and finally enters a
vessel D, into which it is poured when it is completely converted into neutral
carbonate by the heat from a fire-place F placed below, the products of

page_text: combustion from which circulate underneath the tubes and pass through their
whole length in a direction contrary to that of the passage of the salt.
With regard to the humidity and the carbonic acid disengaged, they escape
through the upper tube G, from which they are drawn by the action of a
pump acting lightly. They pass through a water washer in which the
humidity is condensed, the carbonic acid continuing its course and passing
through the pump into the reaction apparatus. The liquor after passing from
the reaction apparatus is next submitted to treatment in the apparatus shewn
at Fig. 4. Heretofore, after having extracted from these liquors the ammonia
and carbonic acid, it was necessary further to extract therefrom the common
salt which had not been destroyed by the chemical reaction. The reaction
upon the salt being according to my Invention complete, it is only necessary
to collect the ammonia. With regard to the small quantity of carbonic acid
which remains therein, it is allowed to be disengaged with this latter, that is
to say, the ammoniacal gas produced is mixed with a small quantity of
carbonate of ammonia, which does not in any way interfere with any of the
operations above described.
On coming from the decanting apparatus the liquor enters direct into a
reservoir A furnished with a levél indicator. This reservoir communicates
freely by means of a pipe a, b, c, with the extremity of the distilling apparatus.
This latter consists of a long tubular vessel B, C, D, the middle of which is
higher and larger than the sides. It is surrounded by a casing at its two
extremities which extend a certain distance and have a certain intermediate
empty space. This space is filled with water which serves two different
purposes. In the part D, C, this water is heated from the outside by two
fire-places; it is carefully enclosed between the two casings, the upper one is
provided with a manometer, safety valve, and other suitable accessories in the
same way as an ordinary steam generator, which office it performs. In the
part B, C, on the contrary, this water only circulates and produces the very
opposite effect, as it cools the liquid and gas inside. The refrigerating water
enters at d and makes its exit at e, after having performed its office. In the
wide part at the middle of the apparatus is a vertical pipe which gradually
widens somewhat towards the bottom, and dips into the liquid inside almost at
the bottom. This pipe has a shaft inside it provided with teeth like a rake
throughout its whole length, and with beaters at bottom, and at top is a
toothed wheel, to which motion is communicated in any suitable manner; this
pipe also communicates towards the top with the reservoir K; at the bottom
are beaters arranged in such manner as to supply to the apparatus a greater
or less quantity of lime according to the speed of rotation. Towards one end

page_text: of the apparatus is a small vertical pipe f, g, having a funnel-shaped top. At
the other extremity the body of the apparatus rises vertically, still surrounded
by its casing, and terminates in a pipe h for the escape of the gas.
The following is the operation of the apparatus:-The liquor enters at c and
fills the apparatus as shewn in the Drawing. The powdered slacked lime is
supplied through the pipe, the reservoir at top being always. full, and the
curved beaters carried by the shaft sweeping it constantly towards the middle
of the reservoir, so that at each revolution of the shaft a portion of lime falls
into the apparatus.
Suppose the apparatus to be at work the following operations take place:-
The liquid filling the forward part D, C, is mixed with lime and heated to a
high temperature by the heated water in the jacket or casing, the ammoniacal
gas will be thereby disengaged, and passing through the whole length of the
apparatus will deposit its humidity as it advances into the hinder cooling part,
carrying off at the same time with it the carbonate of ammonia which is at
that side where there is no lime to decompose it, and finally escapes, as bas
been said, at h; whence it passes to the pipe a, Fig. 2. There is a cock at the
forward part for the passage of the distilled liquid, the flow of which is
regulated according to the height of the liquid in the reservoir A, which
height must always remain about the same. This might be effected by a ball
valve attached to the tap. The heat of the fire must be regulated according
to the pressure of the manometer, which must remain as nearly as possible
uniform, and which is proportional to the heat of the cooling liquid and the
state of the distillation. The first furnace is always strongly ignited, and
the second serves as a regulator, by this means there is a certainty. that the
liquid which flows out continuously shall be perfectly distilled. The agitation
of the liquid in all the front part of the apparatus is violent by reason of the
low temperature, the lime is therefore always stirred throughout. The heating
being effected by means of a liquid is uniform, and not sufficiently violent to
produce internal crusting; this latter is never to be feared. Or the heating
may be effected by means of a bath of chloride of calcium or salt in the open
air, or by means of steam. The top and bottom of the apparatus being
fastened on by bolts may be readily removed when access is required to the
interior. The small pipe f, g, serves for the introduction into the apparatus
of the ammonia necessary for compensating for the losses which cannot be
absolutely prevented in this manufacture, but which are with this apparatus
insignificant. A small plate i below prevents the steam or gas from escaping
through this pipe; this latter is always partially full. of liquid, which is cold
outside, and does not give out any perceptible smell. All loss is likewise

page_text: impossible through the pipe for feeding the lime, which prevents it by forming
a sort of mastic with the liquid which it impregnates, and being continually
renewed. The liquid which flows off is a solution of chloride of calcium
holding in suspension a small quantity of lime in excess and the impurities
which it contains.
.
This distilling apparatus offers several advantages, the principal one of
which is that of extreme simplicity, as the whole operation is conducted in a
single vessel. It also economizes heat and cold. The vaporized ammonia is
cooled by heating the liquors, which have not yet been operated upon in the
cold part of the tube. It produces the introduction and agitation of the lime
by the same movement, it renders incrustation impossible, and furnishes a
certainty that the distillation is always properly completed; the greater the
length given to it the more certain is this result; there is no loss of ammonia,
the work required is very small, and no attention is required to be paid to the
working. The quantity of lime to be introduced is calculated according to
the quantity of liquor run off; they are both measured in vessels adapted to
the purpose, and so many measures of lime are invariably thrown into the
reservoir for so many measures of liquid taken out. Any error on this head
is almost impossible; the workman regulates the speed of the shaft, in order
that it may give out exactly that quantity of lime, and always leave the
reservoir sufficiently well supplied.
Fig. 1 is to be
I have not given the dimensions of the apparatus, which are not important,
but the Drawings, which are drawn to a scale, give the most suitable dimen-
sions; neither have I mentioned the materials of which the apparatus is to
be made, as they may vary, provided due regard being had to the resistance
which they are to offer to pressure, heat, and chemical agents. The following,
however, are those which appear preferable, viz., the vessel of
made of iron, wood, or stone, the vessels of Fig. 2 of wood lined with lead
inside, or of sheet iron carefully tinned, and the other apparatus is made of
sheet, wrought, or cast iron. The reaction apparatus might be tinned inside.
There is no limit to the extent of these apparatuses, the more certainty that
is required in their operation, and the less attention that is required to be paid
to them, the longer they should be made. It may be said that the certainty
of their operation is proportional, to their length. On examining these appa-
ratuses carefully it will be seen that they form, so to speak, but a single
apparatus in consequence of their arrangement. Based all upon the same
principle, they also communicate nearly all of them freely with each other.
First, it is pure water which flows slowly into a conduit of great extent; in
the first place it is charged with salt to the required degree, it then absorbs

page_text: ammonia, of which it determines itself the quantity, and further on always in
flowing it becomes saturated with carbonic acid. At this point only it stops
for an instant to allow the solid product formed within it to be collected,
it soon recommences its interrupted course, gradually freeing itself from a
volatile substance, which it had previously absorbed, and which is constantly
required in the manufacture. Lastly, it runs off retaining in solution a salt,
now of no value, but which will subsequently become of great importance by
the treatment to which it is submitted, and the compounds which are manu-
factured from it. Thus from the vessel of Fig. 1 to the decanting apparatus
it is a simple flowing of a volatile liquid in apparatus hermetically closed. At
this stage the liquid no longer contains any volatile substance, it comes into
contact with the air for one moment without inconvenience, and then re-enters
a closed vessel where it again becomes partially volatile; the loss of ammonia
is therefore inappreciable. By means of this simple arrangement of apparatus
the operation is so perfect that should anything be wanting this will be
indicated by the apparatus itself.
Having thus described the nature of my Invention, and explained the
manner of carrying the same into effect, I desire it to be understood that I
do not claim as part thereof the chemical reactions employed therein, or all
the successive operations which are necessary; but I claim,-
First, the apparatus herein shewn and described, whereby the difference of
density of the simple brine with the ammoniacal brine is applied for effecting
the automatic and continuous supply of ammonia by the difference of level
between the one and the other.
Second, the combination of the means of condensation of the carbonic acid
in the ammoniacal brine, which means consist specially, first, in the employ-
ment simultaneously of the compression of the gas in the liquid and the
division of that gas, so as to multiply the surfaces of contact, of which means
I still further increase the efficacy by the distance travelled by the gas in
the liquid which fills the apparatus; second, in the employment of a washer
in the middle of the operation of condensing the carbonic acid in the ammo-
niacal brine, which is effected by an inverse motion of the liquid and of the
gas. The washer has for its object to neutralize the action of the inert gases
accompanying the carbonic acid, it restores to the liquid before it leaves the
apparatus the ammonia which it lost in entering it by the action of these
inert gases, and thus permits the complete reaction which is desired to be
obtained.
Thirdly, I claim the mode of distilling in a single apparatus the ammonia
from the liquids which contain it. By the arrangement of this apparatus,

page_text: which only allows of the entrance of lime in its middle, the free ammonia is
only disengaged in its front part, and is cooled by the mother liquors in the
back part, from which it carries off the carbonate of ammonia which they
contain in proportion to its traverse; the jet of ammonia is thus regular and
always at the same density.
In witness whereof, I, the said Ernest Solvay, have hereunto set my
hand and seal, the Seventh day of June, in the year of our Lord One
thousand eight hundred and sixty-four.
Witnesses,
HY. AUMUIR,
JOS. SMETS, Jr.
Rue du Commerce, No. 44.
E. SOLVAY.
(L.S.)