IMPROVEMENTS IN APPARATUS FOR CONCENTRATINg Sulphuric Acid. SALINE. AND OTHER SOLUTIONS.”
Year: 1875

page_text: LETTERS PATENT to Manning Prentice, of Stowmarket, in the County
of Suffolk, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
CONCENTRATINg Sulphuric Acid. SALINE. AND OTHER SOLUTIONS.”
CONCENTRATING Sulphuric Acid. SALINE, AND OTHER SOLUTIONS.”
PROVISIONAL SPECIFICATION left by the said Manning Prentice at
the Office of the Commissioners of Patents, with his Petition, on
the 18th December 1875.
.
I, MANNING PRENTICE, of Stowmarket, in the County of Suffolk,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN APPARATUS FOR CONCENTRATING SULPHURIC ACID, SALINE, AND OTHER
SOLUTIONS," to be as follows:-
My Invention relates to apparatus for concentrating sulphuric acid,
saline, and other solutions, by the application of heat which causes a
portion of the water of solution to pass off in the form of vapour,
leaving the residue in the condition of a solution of increased strength.
For this purpose it is usual to place the liquid to be concentrated in
tanks or vessels placed over flues, through which are carried the

page_text: products of combustion from a furnace. It is of advantage to have
these tanks or vessels shallow, so that the bubbles of vapour formed on
their heated surfaces can readily escape through the thin layer of
supernatant liquid. It is also of advantage to have the metal con-
stituting the heated surface of such pans as thin as possible, and
brought as close as possible to the hot gases which play upon it, so
that the heat may pass more rapidly and completely through it to the
liquid operated upon. In many cases the metal employed is of a soft
and yielding character, as for example lead used in the concentration
of sulphuric acid, and has to be supported by some stronger metal such
as iron, and the double thickness of metal thus rendered necessary offers
a considerable obstruction to the passage of the heat to the liquid.
Now the object of my Invention is so to construct and arrange pans
for concentration of liquid as to obtain sufficient strength of bottom
without such thickness of material as would obstruct the passage of
heat and at the same time to increase and improve the heating surface.
For this purpose I make the bottoms of such pans corrugated, placing
the corrugations by preference in a direction transverse to the line of
flue on which the pan is set, so that the products of combustion in their
passage along the flue shall impinge upon the successive prominences
of the corrugations. When the pans are of soft metal, such as lead, I
support them by preference on corrugated iron or copper plates covering
the flues, the bottoms of--the-pans-being-corrugated so as to fit or nearly
fit the corrugations of the plates, so that there may be little loss of
conductivity resulting from the separation of the two metals. Or I
support the corrugated bottoms of the pans on separate narrow bars, so
as to leave the greater part of their surface exposed to the heat, and
when corrugated plates are used they may be perforated for the same
object. I prefer to arrange such pans as I have described, when they
are employed for the concentration of sulphuric acid, in sets at suc-
cessively lower levels. The weak acid after undergoing partial con-
centration in the first pan is allowed to flow into the next to be farther
concentrated, and so on from pan to pan, and when a greater strength
of acid is required than can be obtained by the use of leaden pans, the
final concentration may be effected in pans made of or lined with
platinum. The liquid treated in this manner may be allowed to flow
through the successive pans either intermittently or in a continuous
stream.
f
4

page_text: Although I have described my Invention more particularly as applied
to apparatus for concentrating sulphuric acid, it may be readily under-.
stood that it could be in like manner applied to apparatus_for con-
centrating other liquids, such as saline solutions, soap, and the like, and
that pans constructed and worked, as I have described, might be made
of any suitable metal or other material.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Manning Prentice in the Great Seal Patent Office
on the 17th June 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MANNING
PRENTICE, of Stowmarket, in the County of Suffolk, send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-.
cessors, give and grant unto me, the said Manning Prentice, Her special
license, that I, the said Manning Prentice, my executors, administrators,
and assigns, or such others as I, the said Manning Prentice, my exe-
cutors, 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 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
APPARATUS FOR CONCENTRATING SULPHURIC ACID, SALINE, AND OTHER SOLUTIONS,"
upon the condition (amongst others) that I, the said Manning Prentice,
my executors or administrators, by an instrument in writing (under my,
or their, or one of their hands and seals, should particularly 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 Manning Prentice, 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

page_text: following statement thereof, reference being had to the accompanying
Sheet of Drawings and to the figures and letters marked thereon, that is
to say :-
My Invention relates to apparatus for concentrating sulphuric acid,
saline, and other solutions by the application of heat, which causes a
portion of the water of solution to pass off in the form of vapour,
leaving the residue in the condition of a solution of increased strength.
For this purpose it is usual to place the liquid to be concentrated in
tanks or vessels placed over flues, through which are carried the
products of combustion from a furnace. It is of advantage to have
these tanks or vessels shallow, so that the bubbles of vapour formed on
their heated surfaces can readily escape through the thin layer of
supernatant liquid. It is also of advantage to have the metal con-
stituting the heated surface of such pans as thin as possible and brought
as close as possible to the hot gases which play upon it, so that the heat
may pass more rapidly and completely through it to the liquid operated
upon. In many cases the metal employed is of a soft and yielding
character, as for example lead used in the concentration of sulphuric
acid, and has to be supported by some stronger metal, such as iron, and
the double thickness of metal thus rendered necessary offers a con-
siderable obstruction to the passage of the heat to the liquid.
Now the object of my Invention is so to construct pans or vessels for
concentration of liquid as to obtain sufficient strength of bottom without
such thickness of material as would obstruct the passage of heat, and at
the same time to increase and improve the heating surface. For this
purpose I make the bottoms of such pans corrugated, placing the
corrugations by preference in a direction transverse to the line of flue
on which the pan is set, so that the products of combustion in their
passage along the flue shall impinge upon the successive prominences
of the corrugations. When the pans are of soft metal, such as lead, I
support them by preference on corrugated iron or copper plates covering
the flues, the bottoms of the pans being corrugated so as to fit or nearly
fit the corrugations of the plates, so that there may be little loss of
conductivity resulting from the separation of the two metals. Or I
support the corrugated bottoms of the pans on separate narrow bars
so as to leave the greater part of their surface exposed to the heat, and
when corrugated plates are used they may be perforated for the same
object. I prefer to arrange such pans as I have described, when they
w

page_text: of evaporating or concentrating pans when such pans are heated in a
bath, but I claim,-
First. The use for concentrating by direct heat sulphuric acid; saline,.
and other solutions of shallow pans with corrugated bottoms, having.
their corrugations by preference lying transversely to the direction of
the current in the flue beneath, substantially in the manner and for the
purposes herein described.
Second. Supporting the corrugated bottoms of pans such as are
referred to in the preceding claim by means of plates formed to fit the
corrugations of the pan, substantially as herein described.
In witness whereof, I, the said Manning Prentice, have hereunto
set my hand and seal, this Fifteenth day of June, in the year
of our Lord One thousand eight hundred and seventy-six.
:
MANNING PRENTICE. (L.S.)

page_text: C