IMPROVEMENTS IN AND APPARATUS FOR EXTRACTING AMMONIA FROM SUCH SOLUTIONS AS ARE PRODUCED IN THE DRAGON
Year: 1883

page_text: LETTERS PATENT to Ludwig Mond of Winnington Hall Northwich in the
county of Chester for an Invention of "IMPROVEMENTS IN AND APPARATUS
FOR EXTRACTING AMMONIA FROM SUCH SOLUTIONS AS ARE PRODUCED IN THE
DRAGON
PROVISIONAL SPECIFICATION left by the said Ludwig Mond at the Office
of the Commissioners of Patents on the 9th February 1883.
LUDWIG MOND of Winnington Hall Northwich in the County of Chester,
"IMPROVEMENTS IN AND APPARATUS FOR EXTRACTING AMMONIA FROM SUCH
SOLUTIONS AS ARE PRODUCED IN THE MANUFACTURE OF SODA BY THE AMMONIA
PROCESS.
"
This invention is designed for the purpose of extracting ammonia from solutions
containing both volatile salts of ammonia and those not easily volatile such as the
chloride.
The apparatus consists of a distilling column in two parts, the upper for
extracting free ammonia and its volatile salts, the lower for obtaining ammonia
from the chloride or other non-volatile salts. Into the top of a tall and preferably
circular tower or chamber formed of metal plates or castings I introduce the
ammoniacal liquor; this is caused to fall on a circular dished plate or shallow basin
formed with perforations and denticulations all round so as to divide the liquor
into numerous small streams. The liquor falls from this onto a diaphragm having
a central hole with raised kerb. Over this kerb and through the hole it falls onto
a succession of similar shallow dishes and diaphragms, being all the while in falling
exposed to the action of an upward current of steam or hot gases. The volatile
ammoniacal compounds are by this means extracted from the falling liquor and
escape by a pipe at the top of the tower.
The liquor still containing chloride of ammonium now falls into a chamber
provided with a metallic bell or dome preferably carried on three radial flanges
and having denticulated edge. This bell is partially immersed in a large dished

page_text: diaphragm forming the bottom of the chamber and which has a central tube pro-
jecting upward into the bell. This tube is attached to an oval plate fitting into
an oval hole in the diaphragm. The diaphragm has a tube projecting through it
upwards to a level above the top of the denticulations in the dome and downward
to about the level of the denticulations in the dome below. A series of these
domes and diaphragms and their adjuncts are placed one over another sufficient in
number to separate all the ammonia in the manner hereafter described.
Above the first diaphragm I place an inlet pipe and cock through which I admit
milk of lime. Lower down I prefer to place a second inlet pipe and cock to use in
case sufficient milk of lime has not been supplied by the top one. Each diaphragm
has a depression with a cock at the lowest point to enable me to wash out any
deposit that may from time to time form in the dished diaphragms. Steam is let
in by a pipe at the bottom of the tower passing up into the lowest dome out of
which it forces its way through the liquor, being broken into numerous fine streams
by the denticulations.
Rising up through the central tube of the next diaphragm it again forces its way
through the liquor in small streams through the denticulations and so on till it
escapes into the upper part to perform the operation previously described. The
milk of lime on the contrary with the ammonia liquer is continually descending
overflowing into the diaphragm below as each in succession is filled. The steain
being equally divided all round the dome through the denticulations and following
the slope of the dished diaphragms acts as a perfect agitator and keeps the milk of
lime well mixed with the liquor throughout the apparatus at the same time
preventing the deposit of solid matter in the various compartments. The chloride
of calcium liquor formed escapes at an exit pipe near the bottom. A man hole is
preferably placed between each diaphragm.-

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent and of an
Order of the Lord Chancellor filed by the said Ludwig Mond in the Great
Seal Patent Office on the 17th August 1883.
LUDWIG MOND of Winnington Hall, Northwich in the County of Chester
"IMPROVEMENTS IN AND APPARATUS FOR EXTRACTING AMMONIA FROM SUCH
SOLUTIONS AS ARE PRODUCED IN THE MANUFACTURE OF SODA BY THE AMMONIA
PROCESS,
"
This invention is designed for the purpose of extracting ammonia from solutions
containing both volatile salts of ammonia and those not easily volatile, such as the
chloride, and consists in improvements on the apparatus set forth in Ernest
Solvay's specification N° 1904 of 1876 The apparatus consists, as in Solvay's
specification, of two parts, the upper A for extracting free ammonia and its volatile
salts, the lower B for obtaining ammonia from the chloride or other non volatile
salts. It is best described by aid of the accompanying drawings in which
Fig 1, is a vertical section of the apparatus
Fig 2, enlarged plan of diaphragm of upper part
Fig 3. enlarged plan of dished plate and supports, showing serrations and
perforations.
Fig. 4, enlarged plan of diaphragm in lower part, showing the positions of the
entrance and exit pipes.
Fig. 5, plan of cover or cap.
A is a tall and preferably cylindrical tower, divided by diaphragms into numerous
chambers formed of metal plates or castings, Into this tower at the top as hitherto,
is passed the ammoniacal liquor by means of pipe O. This falls on the circular
dished plate or shallow basin C', formed with perforations and denticulations all
round, so as to divide the liquor into numerous small streams, instead of merely
dripping off the round edge of a convex plate as heretofore. The dished plate is
preferably supported in brackets as shown. The liquor falls from this plate onto
the diaphragm D, meeting in its course the ascending steam and gases hereafter
described the advantage being that instead of the gases having to bubble through the
Liquor, or force their way through a heavy falling stream, they have to pass through
the liquor while divided up into very numerous small streams, themselves so small
as to be almost or quite divided again into separate drops. The diaphragm D has
a small kerb round the central hole. Over this kerb it falls through the hole onto
a second dished plate C, and from thence to diaphragm D¹, and so on through a
succession of C, D, C, D, et cetera. In all these successive falls, the liquor is
exposed to the action of the upward current of steam and hot gases. The volatile
ammonia compounds are by this means extracted from the falling liquor, and escape
by a pipe E at the top of the tower.
The liquor still contains chloride of Ammonium and perhaps other non-volatile
ammoniacal salts; it is now therefore caused to fall into the second or lower
tower B, provided as heretofore with a succession of diaphragms or baffling arrange-
ments; the details of these baffling arrangements are however widely different
from the old arrangement as set forth by Solvay and others, and are designed with
a view of more thoroughly agitating and commingling the materials employed.
They are described as follows. F, F', F2 etcetera, are a series of bells or domes of
cast iron or other suitable material, upon which the liquor falls from the upper
tower, or the diaphragm above, each of them is denticulated at the edge, so as to
break the upward current of steam and gases into numerous finer jets, and is
supported on three radial flanges as shown. It dips down considerably below the

page_text: exit orifice G, (G¹, G², etcetera), so as to cause the gases to bubble through the
liquor collected on the diaphragm J, (J¹, J, etcetera), and well stir the lime or
other sediment collected on the diaphragm. H, (H³, H², etcetera) is the usual orifice
for the gases and steam; it projects into the bell and must not be lower than the
exit orifice G. I, (I', I³, etcetera) is a plate carrying the orifice H, (H¹ H³ etcetera)
and bell F, (F, F etcetera), and is made in an oval form, and fits into an oval seat
in said diaphragm¨J, (J¹, J³,) so that it can be removed and passed in and out
through the seating for repairs etcetera. K, (K¹ K³ etcetera) is the ordinary exit
tube; I make it to project through the diaphragm from a point about the level of
orifice H, (H³, H, et cetera) to near the level of the bottom of diaphragm below,
the said lower diaphragm being depressed at this point to a lower level than any
other part of its circumference; for this purpose a cock mentioned in the provisional
specification but not shown in the drawing, can be placed at the lowest point of
this depression, so as to empty the diaphragm of liquor or wash out any deposit as
required. Lis the usual inlet pipe through which the milk of lime is passed, and M
is a second one which I prefer to use, in case at any time the supply by the upper
pipe becomes too-limited in amount. N is the inlet pipe for steam, which being
adinitted into the lowest bell passes up through one diaphragm after another, till
it reaches the upper tower. The mode of action is similar to that set forth in
Ernest Solvay's specification aforesaid, but as the arrangement of apparatus is so
different I will give it in full.
The Ammonia solution being passed in at the top of the upper tower by pipe O,
the steam at the bottom by pipe N. The milk of lime by pipe L, and occasionally
by pipe M. The ammonia and other gases escape at the top through pipe E, and
the refuse liquor through any convenient waste cock at bottom. The liquor
descending through tower A is deprived of its volatile gases by the upward passago
of steam through it. Arriving at the lower tower B, its chloride, sulphate, or
other non-volatile salts of ammonia are decomposed by the milk of lime, assisted
by the steam, and the caustic ammonia liberated passes upward with the steam,
and off through E.
Having now described my invention and the manner of carrying it into effect, I
claim as my invention to be protected under the letters patent: The manufacture
and use of the various improvements in apparatus for separating ammonia from
liquids formed in the course of manufacturing soda by the ammonia process,
substantially as above set forth.
In witness whereof I the said Ludwig Mond have hereunto set my hand and
seal this third day of August in the year of our Lord one thousand eight hundred
and eighty three.
.Witness
W. P. THOMPSON
Patent Agent
.6 Lord St Liverpool
& 323 High Holborn London.
LUDWIG MOND (L.S.)