Improvements in Apparatuses for Distilling and Purifying Ammoniacal Liquids.
Year: 1886

page_text: Date of Application, 6th July, 1886.
Complete Left, 21st Mar., 1887..
Complete Accepted, 10th June, 1887.
Improvements in Apparatuses for Distilling and Purifying
Ammoniacal Liquids.
I, LOUIS AUGUSTE CHEVALET, of 8, rue de la Chaussée d'Antin, Paris, France,
Engineer, do hereby declare the nature of my said invention for IMPROVEMENTS
IN APPARATUSES FOR DISTILLING AND PURIFYING AMMONIACAL LIQUIDS to be as
follows:-
It is well known that ammoniacal liquids are largely composed of carbonate of
ammonia and sulphydrate of ammonia dissolved in a large quantity of water and some
permanent ammoniacal salts such as chlorhydrate, sulphate and sulphite of ammonia;
the carbonate and the sulphydrate are set free by a simple jet of steam, or by heating
them over a naked fire, and the other salts by the addition of a solution of lime or of
an alkaline carbonate such as carbonate of soda.
The object of my invention is to obtain ammoniacal waters more highly concentrated
than those obtained by the apparatuses at present in use, as the latter generally
speaking, can only produce at the maximum, a concentration of 19° Beaumé; beyond
that degree, the carbonate of ammonia crystallizes in the cooling tubes, stops them up,
and might cause explosions.
In order to give a better idea of my invention, I shall now refer to the accompanying
drawing, representing a distilling and purifying apparatus. This apparatus consists of
a boiler A, a distilling chamber B, an air refrigeratory D, and a condenser L.
My process consists in condensing the ammoniacal vapors arising from the
refrigeratory D, into the ammoniacal water which is to be distilled, or into any other
ammoniacal water should the first mentioned not be thought sufficiently pure. The
ammoniacal vapors arrive in a closed tank, L, of any suitable shape, containing a
cooling worm M; this tank is half or two-thirds full of fresh ammoniacal water; the
ammoniacal vapors bubble in this water and condense in it, enriching it with ammonia,

page_text: When, after a discharge of exhausted water from the boiler A, it is desirable to feed
ammoniacal water into the chamber B, ammoniacal water is pumped into the tank L,
care being taken to leave the tap O shut. The enriched water in the tank L passes
into the chamber B, in which it is distilled; the ammoniacal vapor again comes and
enriches the water in the tank L with ammonia and so on. When it is thought that
the water in the tank is at the desired degree of concentration, it is drawn off into the
cask P.
By this process a concentrated ammoniacal water weighing from 19° to 20° Beaumé
when cold, is obtained in the tank L, the same as by former processes, with this
difference, that it will contain from 25 to 26 per cent. of ammonia instead of 15 per
cent., in fact it will contain as much as sulphate of ammonia.
If instead of concentrated water, carbonate of ammonia in a solid state is desired,
i.e. a salt containing nearly 29 per cent. of ammonia all that would be required would
be to place another reservoir above the reservoir L; these two reservoirs should
communicate with each other, and the upper one should be fed by a stream of cold
water, the lower one being slightly warmed meantime.
The vapors of carbonate of ammonia set free in the reservoir L would be condensed
on the cold walls of the second reservoir forming a continually increasing crust.
By this system of condensation there may also be obtained ammoniacal waters
containing a large percentage of ammonia with a small percentage of carbonic acid;
for this purpose it is only necessary to allow the ammoniacal water in the reservoir L
to heat to about 60° centigrade, in which case the carbonic acid and the sulphydric
acid will be liberated before the ammonia.

page_text: Improvements in Apparatuses for Distilling and Purifying
Ammoniacal Liquids.
I, LOUIS AUGUSTE CHEVALET, of 22, Chaussée d'Antin, Paris, France, Engineer
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the following
statement:-
It is well known that ammoniacal liquids or waters are largely composed of
carbonate of ammonia and sulphydrate of ammonia dissolved in a large quantity of
water, and some permanent ammoniacal salts such as chlorhydrate, sulphate, and
sulphite of ammonia; the carbonate and the sulphydrate are set free by a simple jet of
steam, or by heating them over a naked fire and the other salts by the addition of a
solution of lime or of an alkaline carbonate such as carbonate of soda. This is done in
apparatuses of the most varied form, according to the idea of the operators. The
apparatus shown in the drawing is composed of a distilling chamber B consisting of
three or more vessels or compartments, the said chamber being heated by a
current of steam coming from the tube a a: an air cooler D: and a condenser L.
The ammoniacal liquids to be distilled are forced by a pump H or an upper
reservoir into the distilling chamber B; as they descend successively from one
compartment to another, these liquids lose the carbonate of ammonia and other free
ammoniacal salts which they contain and when they reach the last compartment of the
bottom of the chamber B, they receive a solution of lime from a special force pump
which I need not here describe. The ammoniacal vapors arising from the distilling
chamber B as they pass into the air cooler D become still more concentrated in as
much as the steam which carries off these ammoniacal vapors becomes partly condensed
and returns to the chamber B to be again distilled.
When the ammoniacal vapors
leave the air cooler, they are condensed in any known apparatus, by means of a worm
or vessels surrounded by cold ammoniacal water, or by ordinary water; the condensed
product as it leaves the worm weighs from 15° to 19° degrees Beaumé. The
processes just described are perfectly well known, and are public property, it is only
the apparatuses for putting them in practice which vary; the objection to these processes
is that the ammoniacal waters cannot be concentrated beyond a certain degree which
is generally 19° Beaumé, beyond that, the carbonate of ammonia crystallizes in the
cooling tubes stops them up and may cause the apparatus to explode, unless there
should be a safety valve in the distilling chamber. The process by which I obtain
more highly concentrated ammoniacal liquids consists simply in condensing the
ammoniacal vapors arising from the chamber and from the cooler D, in the ammoniacal
water to be distilled or in any other liquid, should that be found too impure. These
ammoniacal vapors come into a closed reservoir L of any suitable form containing a
cooling worm M; this reservoir is two-thirds full of cold ammoniacal water, the

page_text: ammoniacal vapors bubble in this water and condense in it, thus enriching it with
ammonia. When ammoniacal water is to be fed into the chamber B, the tap O¹ is
kept shut, and the tap O open, after which ammoniacal water is pumped into the
chamber; the water is distilled, the ammoniacal vapor which results adds more ammonia
to the water contained in the reservoir L, and so on. To obtain a water richer of
ammonia it is often desirablo to cool the water in the tank L, for which purpose a
current of cold air entering at c and leaving at c¹ is made to circulate in the worm M;
when it is thought that the water in the reservoir L has reached the desired degree of
concentration, it is drawn off into casks P by the feed pipe or by a special pipe
underneath the tank L. The degree of concentration of the liquid is tested by taking
a sample out of the reservoir L from time to time and weighing it cold by Beaume's
areometer. The gases arising from the tank L and which are composed in a great
measure of carbonic acid, and sulphydric acid, carry off a little ammonia, they are
therefore washed in a bath of cold water placed above the tank L, this little
reservoir is fed by the pump H, the tap O being closed, or by any other suitable
means; the enriched water in the small reservoir passes off by an overflow pipe into
the tank L; it is renewed when found desirable, in order to avoid crystallization of
carbonate of ammonia in the pipe f. If the tanks L and Q are heated, the ammonia
distils and forms sulphate of ammonia in the acid bath G.
The noxious gases arising from the reservoir Q still hold ammonia; they are
conducted to a tank G containing sulphuric acid underneath a leaden bell C hanging
from above such tank; these gases are therefore washed in the acid, leaving in it the
ammonia which thus forms sulphate of ammonia which crystallizes after a certain time;
with regard to the uncondensed gases, they pass off by the pipe g from whence they
are conducted either under a fire to be burnt, or under a purifier in which oxyd of
iron is used. The bell C is intended for the purpose of preventing the escape of noxious
gas. When the acid of the bath G is saturated with ammonia, the salt formed is raked
out and thrown upon the drainer F, after which it is placed upon the drier I to be dried.
To manufacture sulphate of ammonia by means of this apparatus, it is therefore only
necessary to allow the tank L containing the the concentrated ammoniacal liquids to
become heated; the ammonia contained in the liquid held in such tank will then be
distilled with the noxious gases above mentioned.
A variation in the process consists in causing to circulate in the worm M, the ammoniacal
liquid to be distilled, and then directing the latter into the distilling chamber B.
The result is just the same; the water to be distilled is heated at the expense of the
tank L and the overflow of this tank returns to the chamber B by the tube b, b, b. This
apparatus may work continuously or intermittingly; when it works continuously it
is fed by an upper reservoir containing ammoniacal water to be distilled. By this
process I obtain in the tank L which I call the saturator, an ammoniacal water
which will weigh when cold from 19° to 20° degree Beaume, as by previous processes,
only instead of this water containing 15 per cent. of ammonia (NH³) it will contain
from 15 to 26 per cent. i.e. as much as sulphate of ammonia in which form
ammonia is generally sold. This water concentrated to 25 per cent. of ammonia
is very easy to put into casks when its temperature is froin 30 to 35 degrees
centigrade. It can pay a higher charge for carriage since it is richer in ammonia,
it is therefore quite different form that obtained by former systems.
If instead of concentrated liquid solid carbonate of ammonia be required, it would
only be necessary to place above the tank L, another tank, and connect them by a
wide tubing. A jet of cold water would be directed against this upper reservoir, and
the lower one L would be allowed to heat slightly so as to distil the curbonate of
ammonia. Under such conditions, the carbonate of ammonia arising from the tank L
would condense upon the cold sides of the second tank and form a continually
increasing crust. It is obvious that the second tank or vessel should be so constructed
as to allow of the removal of the solid carbonate of ammonia contained in it.
By making the saturating tank L of greater capacity it would become a magazine
or store of ammonia requiring less water to cool it since its greater extent of surface
would enable the air to exert a greater cooling influence. This apparatus is more

page_text: especially suitable for purifying the ammoniacal liquids of gas works from the carbonic
acid, and sulphydric acid which they contain; for that purpose all that is required is
to keep the ammoniacal waters in the tank L at the boiling point for a certain time,
this drives off the carbonic and sulphydric acids and leaves the ammonia as nearly as
possible in solution in the water. This boiled ammoniacal liquid is rich in ammonia
though of slight density when tested by the areometer; it is particularly suitable,
when cold for washing coal gas and removing its carbonic and sulphydric acid, for
commencing the purifying process in fact. By such washing the ammoniacal liquid
becomes dense again in as much as it absorbs the carbonic and sulphydric acids of the
gas; but by passing it again through the concentrating apparatus these gases are
once more removed and it becomes fit to wash the gas as before. By proceeding as
above the ammoniacal liquid boiled in my apparatus is made to serve as a purifying
agent for gas works.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I
claim is :
1° The use of the tanks or vessels L and Q and of the system of condensation
above described, in any distilling apparatus whether already known or not, for
obtaining liquids which shall be rich in ammonia.
2° The use of the 2nd tank L and the process described in connection therewith
for obtaining solid carbonate of ammonia.
3° The connection of the air cooler D with my condensing tank L for more easily
obtaining concentrated ammoniacal liquids.
4° The use of the distilling apparatus and the process above described for obtaining
purified ammoniacal liquids suitable for purifying gas.
Dated this Twenty first day of March 1887.
A. 11. REED,
Agent.