IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSIAS
CHRISTOPHER GAMBLE, of Saint Helen's, in the County of Lancaster, Manų-
facturing Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Fourth day of December, in the eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Josias Christopher Gamble, Her especial licence, full power, sole privi-
lege and authority, that I, the said Josias Christopher Gamble, my executors,
administrators, and assigns, and such others as I, the said Josias Christopher
Gamble, my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein mentioned, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID;" in
which said Letters Patent is contained a proviso obliging me, the said
Josias Christopher Gamble, by an instrument in writing under my hand and
seal, particularly to describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, and to cause the same
to be enrolled in Her Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more
fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Josias Christopher Gamble, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, is particu-
larly described and ascertained in and by the following description thereof,
reference being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say) :-
My improvements in the manufacture of sulphuric acid consist in the
abstraction of the heat produced by the combustion of the metallic sulphurets
employed in such manufacture, and applying it to the evaporation of acid and
saline solutions. The bi-sulphurets of iron and copper are the metallic sul-
phurets employed in this manufacture, and the high heat produced by their
combustion is highly injurious to the leaden chamber, rendering the sulphuric
acid produced less pure, whilst at the same time it retards its formation. The
method whereby I extract the heat and apply it to the purpose of evaporation
will be seen by reference to the Drawings, in which Fig. 1 represents in
longitudinal elevation the furnace I employ; Fig. 2 is a front view of the
same; Fig. 3 is a vertical section taken in the line 1, 2, Fig. 2, shewing
the kilns and their connection with the chimney shaft; and Fig. 4 is a hori-
zontal section taken in the line 3, 4, Fig. 1, shewing the construction of the
nitric acid flue. A, A, A, A, are four kilns for burning pyrites. B, B, is the
flue in which nitric acid gas is produced, and C the flue to conduct it to the
chimney D.. The nitre pots are put in at one end of the flue B, and are
withdrawn at the other. The apertures are all closed with doors when not
in use, excepting those used for discharging the pyrites. Above the flue C,
and opening into the chimney, are three flues E (see the dotted lines Fig. 4),
which conduct the sulphurous acid gas away from the kilns A. By this
arrangement the nitric acid gas and sulphurous acid gas are kept separate
until they enter the chimney, from whence they proceed to the leaden chamber
F. The kilns are usually inverted quadrangular truncated pyramids, fifteen
inches in diameter at bottom, three feet wide at top, and eight feet deep.
They are constructed in the usual way, with doors for charging and stirring
the materials, and have an opening for drawing or discharging the materials.
G is an arched vault to allow of a passage or opening being made for the dis-
charge of the kilns next it, one of which openings is shewn at H; the other
kilns are discharged at the openings I, I. Over the kilns an arch is turned tens
feet in length; the groins of the arch are filled up to a level with a crown, so as
to form a level bed for supporting the leaden evaporating pan. K, L, and M,
are two other leaden evaporating pans placed over the flue E, and supported
in their place by bars of iron resting upon the walls of the furnace. These

page_text: pans I prefer applying to the concentration of sulphuric acid; they are each ten
feet long by six feet wide. Weak acid is introduced into the pan M, next
the chamber F, at about 1.520 specific gravity, and brought forward by
degrees to the pan K, where it is concentrated to 1.750. The pan M is
raised two inches above the pan L, and that two inches above K. I find
these pans fully equal to concentrate the sulphuric acid produced by the
above kilns and their corresponding capacity of chambers. If it should be
thought advisable to concentrate soda or common salt solutions, a single pan of
iron might be substituted for the leaden pans above described. The flues
conveying the sulphurous acid gas being liable to get stopped up from time to
time by th sublimation of volatile metallic oxides, it will be advantageous to
have holes at the ends of these flues near the chimney, for the purpose of
cleaning them occasionally.
I do not claim as my Invention any particular form of kilns or evaporating
vessels for conducting the above manufacture, but I have described above
those which I find most advantageous to employ.
I claim as my Invention, under the before in part recited Letters Patent, the
application of the heat produced by the combustion of bi-sulphurets of iron and
copper in making sulphuric acid for the purpose of concentrating the said
sulphuric acid, and other saline solutions.
In witness whereof, I, the said Josias Christopher Gamble, have hereunto
set my hand and seal, the Twenty-first day of May, in the year of
our Lord One thousand eight hundred and forty-five.