IMPROVEMENTS IN BLEACHING, PURIFYING, AND CONCENTRATING SULPHURIC ACID PARTS OF WHICH INVENTION ARE APPLICABLE TO EVAPORATING
Year: 1852

page_text: LETTERS PATENT to Charles Barlow, of Chancery Lane, London,
for the Invention of "IMPROVEMENTS IN BLEACHING, PURIFYING, AND
CONCENTRATING SULPHURIC ACID PARTS OF WHICH INVENTION ARE
-
A
PROVISIONAL SPECIFICATION left by the said Charles Barlow at
the Office of the Commissioners of Patents, with his Petition,
on the 16th December 1852.
I, CHARLES BARLOW, of Chancery Lane, London, do further
declare the nature of the said Invention of "IMPROVEMENTS IN
BLEACHING, PURIFYING, AND CONCENTRATING SULPHURIC ACID, -
-
WHICH INVENTION ARE APPLICABLE TO EVAPORATING OTHER LIQUIDS," to be
as follows:.
It is well known that sulphuric acid when it issues from the
leaden chambers in which it is produced, is of a yellow colour,
caused by the presence of hypoazotic acid formed during the process.
This hypoazotic acid is ordinarily disengaged in the form of red
vapours when the sulphuric acid is heated, from which disagreeable
results flow, such as dangerous exhalations, with loss of produce.
To obviate which I propose to cover the boiler which receives the

page_text: sulphuric acid from the leaden chambers with a moveable cover or
capital of lead, the edges of which are in the acid. Under the cover
I cause a current of sulphuric acid gas to circulate, which combines
with the red vapors of the hypoazotic acid disengaged by
the heat, thus forming liquid sulphuric acid which remains in
the boiler. I cause the residue of the sulphurous and nitrous gases
which are not combined to pass into the pipe of the great sulphur
furnace, whence they are carried back into the leaden chambers.
The sulphuric acid, thus bleached and purified, is conducted into
a second evaporating boiler of lead, to be there concentrated. Over
the boiler I place a moveable condensing capital or cover suspended
by cords passing over pullies in order to raise it, to permit atmo-
spheric air to circulate over the surface of the liquid in order to
induce rapid evaporation. This capital or cover has in its interior
sides a gutter, into which the condensed liquid flows; this prevents
the condensed liquid from again flowing to the boiler, and the
capital or cover admits of quick condensation. The capital or cover,
although of the same size as the boiler, does not hermetically close
it, which would be dangerous. When the sulphuric acid is sufficiently
condensed, it is conducted to a reservoir, where it cools, and the
boiler is filled again as before. To avoid the loss of gases which
escape from the chamber of lead, I employ the apparatus described
of Gay Lussac, such as pipes containing sulphuric acid & reservoirs
containing coke, together with the apparatus for absorption con-
taining alkalin solution agitated by the palettes of a revolving axis
invented by Mr. Lautter. Other liquids may be evaporated by
similar means..
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said Charles Barlow in the Great Seal
Patent Office on the 15th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
CHARLES BARLOW, of Chancery Lane, London, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date at Westminster the Sixteenth day of De-
cember, in the year of our Lord One thousand eight hundred and fifty-
two, in the sixteenth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Charles Barlow, Herspecial
licence that I, the said Charles Barlow, my executors, administrators,
and assigns, or such others as I, the said Charles Barlow, 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 night make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention, communicated
to me by a certain foreigner residing abroad, to wit, Dominique
Emile Coutaret, of Roxbury, in the County of Norfolk, and State of
Massachussets, in the United States of America, Chemist, for "IM-
PROVEMENTS IN BLEACHING, PURIFYING, AND CONCENTRATING SULPHURIC ACID-
PARTS OF WHICH INVENTION ARE APPLICABLE TO EVAPORATING OTHER LIQUIDS,"
upon the condition (amongst others) that I, the said Charles Barlow,
by an instrument in writing under my hand and seal, should par-
ticularly 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 Charles Barlow, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and
by the following statement (that is to say):-
In the manufacture of sulphuric acid or oil of vitriol, as commonly
practised, there is a considerable loss, and noxious emanations escape,
which are prejudicial to health, and the object of my Invention is
to obviate these evils or disadvantages. Sulphuric acid, when it
issues from the leaden chambers ordinarily employed at fifty degrees
Beaumé, or of specific gravity 1.547 to 1.594, is usually of a yellow
color, owing to the presence of hyponitric or hypoazotic acid, which
is formed during the process of manufacture, and which is dis-

page_text: engaged in the form of red vapors at the time when the sul-
phuric acid is heated to concentrate it in the leaden evapo.
rating boilers commonly used; and this disengagement causes
a noxious smell dangerous to the health of the workmen and
to the neighbourhood, and the loss of acid alluded to. Το
avoid this double disadvantage, and to bleach the sulphuric
acid, I cover the boiler which receives it from the leaden chainbers
with a moveable cover of lead, the edges of which plunge into
the acid, and under which I cause a current of sulphurous acid
gas to circulate. This acid gas combines with the red vapors of
the hyponitric or hypoazotic acid, which are disengaged by the
heat, and forms again liquid sulphuric acid, which remains in the
boiler. I cause the residue of the sulphurous and nitrous gases
which are not combined to pass into the pipe of the great sulphur
furnace, whence they are carried back into the leaden chambers.
In this mode I effect the bleaching and purification of sulphuric
acid without injury to workmen or the neighborhood, and I avoid
the heavy loss of the nitrous products. The sulphuric acid thus
bleached and purified is afterwards conducted into a second
evaporating boiler of lead, to be there concentrated, but there also
another evil ordinarily presents itself. When the temperature
of the sulphuric acid is raised to effect the concentration, the steam
which is formed carries with it a larger or smaller quantity of acid,
which may still annoy the workmen and injure the neighbourhood,
at the same time that it causes a loss to the manufacturer. I have
succeeded in preventing these pernicious effects by placing above
the evaporating boiler a moveable condensing capital or cover sus-
pended by cords passing over pullies, in order to raise it to the proper
height to permit the atmospheric air to circulate over the surface of
the liquid, a condition necessary to promote rapid evaporation, and
to avoid the fusion of the lead of which the boiler is formed. This
capital or cover, which is of the same size as the boiler, is surrounded
on its lower interior margin by a gutter, into which flows the liquid,
which is condensed upon the whole interior surface of the capital
or cover on which the vapors of the acid arc thrown with an
ascending force which increases with the temperature, and which

page_text: causes them to traverse the current of atinospheric air which
circulates on the surface of the acid contained in the boiler, without
spreading into the works or its vicinity. If the capital or cover
were to cover the boiler, closing it hermetically (like the capital of an
alembic), there would be danger of bursting the boiler, and evapora-
tion would be stopped, or proceed very slowly, on account of the small
aperture with the passage of a serpentine offers; for all the liquid
forined in the capital or cover by condensation would fall back
again into the boiler, an effect which does not take place with the
gutter, which receives the product of the condensation of my-sus-
pended capital or cover. Another advantage of my Invention is in
accelerating the process, as this capital or cover, being isolated in the
air, receives none of the heat of the furnace, which it does not touch,
so that condensation is continually effected as rapidly as the evapora-
tion, which cannot happen in a capital brought in contact with the
boiler. When the sulphuric acid has attained the degree of con-
centration to which it is desired to be brought, it is conducted into
a reservoir, where it cools, and the boiler is filled again with the
bleached and purified acid contained in the upper boiler, into which
more acid is drawn off from the chambers, to continue without
interruption the process of purification and concentration. To
avoid the loss and emanations of gases, which escape from the
chambers of lead, I employ the apparatus described by Gay Lussac,
such as pipes containing sulphuric acid, and reservoirs containing
coke, together with the apparatus for absorption containing alkalinė
solutions agitated by the palettes of a revolving axis invented and
patented by Mr. Sautter, and described in the Repertory of Patent
Inventions, London, August, One thousand eight hundred and
forty-three.
EXPLANATION OF THE DRAWING.
A, the leaden boiler, receiving the acid from the chambers of
lead; B, leaden cover suspended by cords and pullies, f, ff, the
edges of which enter the boiler and plunge into the acid; C, a
small furnace let into the masonry for burning the sulphur and
the production of the sulphuric acid; D, pipe conducting the

page_text: sulphurous gas from the furnace C, under the cover B; E, pipe
conducting the gases which are not condensed from the cover B, into
the leaden chambers of the factory; F, brick furnace for the two
boilers, having a single fire at K; G, leaden evaporating boiler
receiving the purified acid from the boiler A, by the syphon M; H,
leaden condensing capital or cover suspended by cords and. pullies f,
ff above the boiler G; I, pipe for the flowing of the liquid
condensed in the gutter of the suspended capital or cover H;
J, receiver; K, door of the furnace; I, flue of the chimney; M,
syphon of communication between the two boilers A, and G; N,
solid woodwork which supports the pullies by means of which the
capitals or covers can be raised to the proper degree of elevation
for the purposes above described, and for cleansing or necessary
repairs. It will be obvious to those acquainted with chemical
manufactures, that the same kind of moveable cover or capital may
be employed in connection with other suitable apparatus for
evaporating other liquids.
Having now described the nature of the said Invention, and how
the same is to be performed, I would have it understood that I
do not confine myself to the precise details herein-before described or
shewn; but I claim the mode of bleaching, purifying, and concen-
trating sulphuric acid from leaden chambers by means of moveable
capitals or covers (one of which is surrounded by a gutter), as
herein-before described and shewn by the annexed Drawings, adapted
to the evaporating boilers employed in chemical factories or works;
and I claim the use or application of the herein-before described and
shewn apparatus for evaporating other liquids.
In witness whereof, I, the said Charles Barlow, have hereunto
set my hand and seal, this Fifteenth day of Junc, in the year
of our Lord One thousand eight hundred and fifty-three.
CHARLES BARLOW. (L.S.)