IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID
Year: 1856

page_text: LETTERS PATENT to James Lawrence Crockett, of West Ham, in the
County of Essex, Manufacturer, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF SULPHURIC ACID."-A communication.
Sealed the 5th December 1856, and dated.the 19th July 1856.
PROVISIONAL SPECIFICATION left by the said James Lawrence Crockett
at the Office of the Commissioners of Patents, with his Petition, on
the 19th July 1856.
I, JAMES LAWRENCE CROCKETT, of West Ham, in the County of Essex,
Manufacturer, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID," a communication from
abroad, to be as follows:-
This Invention relates to an improved construction and combination of
furnace and tank for effecting the concentration of sulphuric acid, whereby the
destruction of the leaden chambers hitherto employed for that purpose, or the
use of platinum stills, is obviated.
According to this Invention the concentrating tank is composed of the
following parts-First, an inner casing of fire tiles, or other cheap material
not acted upon by hot sulphuric acid, the joints of which need not be made
absolutely liquid-tight; second, a layer of sand, supported by, third, another
similar casing of tiles; fourth, another layer of sand contained in a casing of

page_text: lead. Exterior to this lead casing is another similar casing of lead, a space
being left between the two for the purpose of holding water if considered
desirable. These several casings and layers of sand extend over the whole
bottom and sides of the tank. The heat to cause evaporation is derived by
radiation from an overhead heating arch, built of fire brick, & forming at the
same time the roof of the concentrating chamber and the floor of the heating
flue, which may proceed direct from the fire-place to the chimney. Now, if
when the acid to be concentrated is placed inside the tank any percolation
through the joints of the brick casings and sand should ensue, the acid which
penetrates to the inner lead casing will be so cooled that it will exercise very
little influence thereupon. My object in employing the inner leaden casing is
to prevent any escape or loss of acid in case the joints of the tiles should not
be perfectly liquid-tight, and the object of filling the space between the two
leaden cases with cold water is to keep such acid as may find its way to the
inner leaden casing as cold as possible, though I do not consider cold water in
this space absolutely necessary. Suitable inlets and outlets are employed for
facilitating the introduction of fresh weak acid and the escape of the gases
and aqueous vapor evolved during the concentrating process. By suitable
arrangements, well known to those employed in the concentration of sulphuric
acid, the tank may be fed with weak acid by means of a siphon, whilst the
acid which has undergone the process of concentration may be removed by
similar means.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Lawrence Crockett in the Great Seal Patent Office
. on the 19th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
LAWRENCE CROCKETT, of West Ham, in the County of Essex, Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by IIer Letters
Patent, bearing date the Nineteenth day of July, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said James
Lawrence Crockett, Her special license that I, the said James Lawrence
Crockett, my executors, administrators, and assigns, or such others as I, the
said James Lawrence Crockett, my executors, administrators, or assigns;
should at any time agree with, and no others, from time to time and at all

page_text: 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 "Im-
PROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID," a communication from
abroad, upon the condition (amongst others) that I, the said James Lawrence
Crockett, 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 James Lawrence Crockett, 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, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :--
The said Invention relates to an improved construction and combination of
furnace and tank for effecting the concentration of sulphuric acid, whereby
the destruction of the leaden chambers hitherto employed for that purpose, or
the use of platinum stills, is obviated.
According to this Invention the concentrating tank is composed of the
following parts: First, an inner casing of fire tiles, or other cheap material
not acted upon by hot sulphuric acid, the joints of which need not be made
absolutely liquid-tight; second, a layer of sand, supported by, third, another
similar casing of tiles; fourth, another layer of sand contained in a casing of
lead. Exterior to this lead casing is another similar casing of lead, a space
being left between the two for the purpose of holding water if considered
desirable. These several casings and layers of sand extend over the whole
bottom and sides of the tank. The heat is derived by radiation from an over-
head heating arch, built of fire brick, and forming at the same time the roof
of the concentrating chamber and the floor of the heating flue, which may
proceed direct from the fire-place to the chimney. Now, if when the acid to
be concentrated is placed inside the tank any percolation through the joints
of the brick casings and sand should ensue, the acid which penetrates to the
inner lead casing will be so cooled that it will exercise very little influence
thereupon. My object in employing the inner leaden casing is to prevent any
escape or loss of acid in case the joints of the tiles should not be perfectly
liquid-tight, and the object of filling the space between the two leaden cases
with cold water is to keep such acid as may find its way to the inner leaden
casing as cold as possible, though I do not consider cold water in this space

page_text: absolutely necessary. Suitable inlets and outlets are employed for facilitating
the introduction of fresh weak acid and the escape of the gases and aqueous
vapour evolved during the concentrating process.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the Figures on the Sheet of Drawings hereunto annexed, the same
letters of reference indicating corresponding parts throughout both Figures.
Figure 1, of the Drawings, represents a longitudinal vertical section of the
improved concentrating apparatus; and Figure 2 is a corresponding tranverse
section of the same taken along the line 1, 2, in Figure 1. A is the concen-
trating tank; b, the inner casing of fire tiles; c, the first layer of sand; d, a
second layer of fire tiles; c', the second layer of sand; and e, the leaden
casing which encloses the above enumerated materials; B is the second or
outer leaden casing, which forms a cold-water tank, surrounding the sides and
bottom of the concentrating tank or chamber. By this means any acid which
may percolate through the tiles and sand will be prevented from being lost,
and will be kept perfectly cool by the water which surrounds the inner leaden
casing. C is the furnace, which opens direct into the overhead heating flue D,
the bottom of which forms the roof or cover to the concentrating tank. This
flue opens into the chimney E by being placed above the tank; it is less liable
to injure the same, whilst at the same time a more even temperature is
obtained. Suitable inlets and outlets F and G are employed for facilitating
the introduction of fresh weak acid and the escape of the gases and aqueous
vapor evolved during the process of concentration.
It is obvious, that by suitable arrangements, well known to those employed in
the concentration of sulphuric acid, the tank may be fed with weak acid by
means of a syphon, whilst the acid which has undergone the process of con-
centration may be removed by similar means. A number of these tanks may
also be arranged at different elevations, the acid being made to pass from the
top tahk successively through the rest, until it finally emerges at the desired
strength.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of the said Invention; but
what I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,-

page_text: First, the general construction and arrangement of apparatus for concen-
trating sulphuric acid, as herein-before described.
Second, the application and use of tanks employed in the concentration of
sulphuric acid, the bottom and sides of which are composed of alternate layers
of fire tiles and sand enclosed in a leaden casing, as herein-before described.
In witness whereof, I, the said James Lawrence Crockett, have hereunto
set my hand and seal, the Nineteenth day of January, One thousand
eight hundred and fifty-seven.
J. LAWRENCE CROCKETT. (L.S.)
Signed, sealed, and delivered in the
presence of
J. HENRY JOHNSON,
47, Lincoln's Inn Fields.