IMPROVEMENTS IN THE MEANS OF AND APPARATUS FOR MANUFACTURING SULPHATE OF AMMONIA AND SULPHURIC ACID
Year: 1864

page_text: LETTERS PATENT to James Forbes, of Old Ford, Bow, in the County of
Middlesex, Manufacturing Chemist, for the Invention of "IMPROVEMENTS
IN THE MEANS OF AND APPARATUS FOR MANUFACTURING SULPHATE OF AMMONIA
AND SULPHURIC ACID."
Sealed the 20th December 1864, and dated the 21st June 1864.
PROVISIONAL SPECIFICATION left by the said James Forbes at the
Office of the Commissioners of Patents, with his Petition, on the
21st June 1864.
I, JAMES FORBES, of Old Ford, Bow, in the County of Middlesex, Manu-
facturing Chemist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MEANS OF AND APPARATUS FOR MANUFACTURING SULPHATE
OF AMMONIA AND SULPHURIC ACID," to be as follows:-
This Invention consists in certain improvements in the manufacture of
sulphate of ammonia and sulphuric acid from or by means of the agency of
sulphuretted hydrogen gas disengaged during the process of saturating
sulphuric acid with ammoniacal vapour.
From a suitable reservoir or feed head elevated above the apparatus a
supply of ammoniacal liquor is obtained, which liquor is conducted through a

page_text: series of horizontal pipes connected end to end to a column or still, the liquor
flowing down from the various surfaces of the still, and becoming heated and
transformed to the gaseous state by means of steam at high pressure supplied
to the lower part of the still. These horizontal conducting tubes are encased
or surrounded by larger tubes, their junctions being effected by right-angled
tubes and flanges, the lowest of these enlarged tubes communicating with a
worm in a water condenser, which worm continues below into a receptacle
for the condensed liquor. From this receptacle a pipe is connected with a
sulphur furnace, by the side of which is a nitre furnace, from each of which &
vertical pipe conveys sulphuretted hydrogen and nitrous acid respectively into
a horizontal pipe, and thence into a vitriol chamber above and beyond them,
such chamber being supported by suitable standards and framing.
Now the operation or working of the apparatus in order to manufacture
sulphate of ammonia and sulphuric acid is as follows, and it will be observed
that the sulphuric acid is made from the sulphuretted hydrogen gas which is
disengaged during the process of saturating sulphuric acid with ammoniacal
vapour. Let us assume, for the sake of description, that the sulphuretted
hydrogen derived from the ammoniacal liquor is conveyed to the sulphur
furnace in which a quantity of brimstone is burning; let us also assume that
the nitrate of potash in the nitre furnace is being burnt; then there will result
the sulphurous acid fumes, and the fumes of nitrous acid, which uniting in the
vitriol chamber will form sulphuric acid.
When the steam is supplied to the still or column the ammoniacal liquor
will become heated, and evaporation of ammonia and sulphuretted hydrogen
will ensue; this gas is conducted by a pipe to a saturating vessel containing
sulphuric acid diluted, which sulphuric acid is obtained, as just described, as
an ulterior process from the surplus sulphuretted hydrogen eliminated from
the ammoniacal liquor.
Now the pipe which conducts the sulphuretted hydrogen from the still
to the saturator lies along the bottom of the saturating vessel, and is
perforated with a series of rose openings, through which the sulphuretted
hydrogen and steam are forced; the diluted sulphuric acid thus becomes
saturated, and is changed into sulphate of ammonia in solution, which
may be drawn off by a tap and evaporated to crystals or the dry salt. The
surplus sulphuretted hydrogen and steam rises above the surface of the
diluted acid, and passes off by a pipe at the top of the saturating vessel into
the uppermost of the series of large pipes surrounding the small pipes which
convey the ammoniacal liquor from the reservoir to the still. The result is, of
course, obvious, the enlarged pipes form jackets or heaters for the ammoniacal

page_text: liquor, and the heat being removed or transferred from the steam and hydrogen
to the ammoniacal liquor, the latter enters the still highly heated and ready
for evaporation, whereas the steam and sulphuretted hydrogen become cooled
to a certain extent, and passing through the further series of pipes in the
water condenser become ultimately cooled and condensed, and fall into a
separating vessel below the water condenser; this vessel is furnished with
pipes and traps for the control of the foul liquor. The sulphuretted hydrogen
is then conducted by the pipe first described into the sulphur furnace, and the
vitriol is formed thereby and by union with nitrous acid, as before stated.
It will thus be evident that the process is throughout continuous, all parts
of the apparatus being in operation simultaneously. The steam and sul-
phuretted hydrogen are therefore first partly condensed by the outer contact
of the air, and the internal conduction of heat by the pipe conveying the
ammoniacal liquor, and afterwards by the water condenser.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Forbes in the Great Seal Patent Office on the
21st December 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
FORBES, of Old Ford, Bow, in the County of Middlesex, Manufacturing
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of June, in the year of our Lord One
thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Forbes, Her special license that I, the said James Forbes,
my executors, administrators, and assigns, or such others as I, the said
James Forbes, my executors, administrators, or 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 "IMPROVEMENTS IN
THE MEANS OF AND APPARATUS FOR MANUFACTURING SULPHATE OF AMMONIA AND
SULPHURIC ACID," upon the condition (amongst others) that I, the said James
Forbes,
executors or administrators, by an instrument in writing under
my hand and seal, or under the hand and seal of one of them, should par-
ticularly describe and ascertain the nature of the said Invention, and in what

page_text: 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 James Forbes, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement :-
This Invention consists in certain improvements in the manufacture of
sulphate of ammonia and sulphuric acid from or by means of the agency of
sulphuretted hydrogen gas disengaged during the process of saturating
sulphuric acid with ammoniacal vapour.
From a suitable reservoir or feed head elevated above the apparatus a
supply of ammoniacal liquor is obtained, which liquor is conducted through a
series of horizontal pipes connected end to end to a column or still, the liquor
flowing down from the various surfaces of the still, and becoming heated
and transformed to the gaseous state by means of steam at high pressure
supplied to the lower part of the still. These horizontal conducting tubes are
encased or surrounded by larger tubes, their junctions being effected by right-
angled tubes and flanges, the lowest of these enlarged tubes communicating
with a worm in a water condenser, which worm continues below into a
receptacle for the condensed liquor. From this receptacle a pipe is connected
with a sulphur furnace, by the side of which is a nitre furnace, from each of
which a vertical pipe conveys sulphurous acid, sulphuretted hydrogen, and
nitrous acid respectively into a horizontal pipe, and thence into a vitriol
chamber above and beyond them, such chamber being supported by suitable
standards and framing.
Now, the operation or working of the apparatus in order to manufacture
sulphate of ammonia and sulphuric acid is as follows, and it will be observed
that the sulphuric acid is made from the sulphurous acid gas which is
disengaged during the process of saturating sulphuric acid with ammoniacal
vapour.
.
Let us assume, for the sake of description, that the sulphuretted hydrogen
derived from the ammoniacal liquor is conveyed to the sulphur furnace in
which a quantity of brimstone is burning; let us also assume that the nitrate
of potash or nitrate of soda in the nitre furnace is being burnt, then there will
result the sulphurous acid fumes and the fumes of nitrous acid, which uniting
in the vitriol chamber will form sulphuric acid.
When the steam is supplied to the still or column the ammoniacal liquor
will become heated, and evaporation of ammonia and sulphuretted hydrogen

page_text: will ensue; this gas is conducted by a pipe to a saturating vessel containing
sulphuric acid diluted, which sulphuric acid is obtained, as just described, as
an ulterior process from the surplus sulphuretted bydrogen eliminated from
the ammoniacal liquor.
Now the pipe which conducts the sulphuretted hydrogen from the still to
the saturator lies along the bottom of the saturating vessel, and is perforated
with a series of rose openings, through which the sulphuretted hydrogen and
steam are forced; the diluted sulphuric acid thus becomes saturated, and is
changed into sulphate of ammonia in solution, which may be drawn off by a
tap, and evaporated to crystals or the dry salt. The surplus sulphuretted
hydrogen and steam rise above the surface of the diluted acid, and passes off
by a pipe at the top of the saturating vessel into the uppermost of the series
of large pipes surrounding the small pipes which convey the ammoniacal
liquor from the reservoir to the still. The result is, of course, obvious, the
enlarged pipes form jackets or heaters for the ammoniacal liquor, and the
heat being removed or transferred from the steam and hydrogen to the
ammoniacal liquor, the latter enters the still highly heated and ready for
evaporation, whereas the steam and sulphuretted bydrogen become cooled to
a certain extent, and passing through the further series of pipes in the water
condenser become ultimately cooled and condensed, and fall into a separating
vessel below the water condenser; this vessel is furnished with pipes and traps
for the control of the foul liquor. The sulphuretted hydrogen is then conducted
by the pipe first described into the sulphur furnace, and the vitriol is formed
thereby and by union with nitrous acid, as before described. It will thus be
evident that the process is throughout continuous, all parts of the apparatus
being in operation simultaneously. The steam and sulphuretted hydrogen are
therefore first partly condensed by the outer contact of the air and the internal
conduction of heat by the pipe conveying the ammoniacal liquor, and after-
wards by the water condenser.
In order that my Invention may be more completely understood, I annex a
Drawing shewing the arrangement of apparatus.
a represents the boiler, and 6 the steam pipe leading to the still; c is the
guage glass; d, the outlet; e, the pipe from still to saturator f; g, the bent
tube from superheater h to still; i, the pipe to feed head; j, the water
condenser; k, pipe to saturator; 1, pipe leading to foul separator m;
n, sulphuretted hydrogen pipe to sulphur furnace o; p, pipe for conveying
sulphurous and nitrous and nitrous acid to vitriol chamber q.
Having now described the nature of my said Invention, and the manner in
which the same is to be performed, I would remark, in conclusion, that I do

page_text: not limit myself to the precise details and configuration of parts I have
expressed and shewn, nor to any dimensions of apparatus, as the same may
obviously be varied or modified without departing from the principles on
which the manufacture is based; I am aware that the column or still is not
new; what I claim and desire to be secured to me by the herein in part
recited Letters Patent is, the general arrangement and combination of
apparatus, substantially as herein specified, whereby I am enabled to
manufacture sulphate of ammonia and sulphuric acid by the process
described.
In witness whereof, I, the said James Forbes, have hereunto set my 1
hand and seal, this Nineteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-four.
Witness,
ALEX³. PRINCE,
Office for Patents,
4, Trafalgar Square,
Charing Cross.
JAMES FORBES. (L.S.)