IMPROVEMENTS IN THE MODE OF CONCENTRATING SULPHURIC ACID AND IN APPARATUS FOR THE SAME
Year: 1883

page_text: LETTERS PATENT to Samuel Bowen Bowen of Llanelly in the County
of Carmarthen for an Invention of IMPROVEMENTS IN THE MODE OF
CONCENTRATING SULPHURIC ACID AND IN APPARATUS FOR THE SAME
PROVISIONAL SPECIFICATION left by the said Samuel Bowen Bowen at
the Office of the Commissioners of Patents on the 21st April 1883.
SAMUEL BOWEN BOWEN of Llanelly in the County of Carmarthen
« IMPROVE-
MENTS IN THE MODE OF CONCENTRATING SULPHURIC ACID AND IN APPARATUS FOR
THE SAME,"
"
This invention relates to an improved mode of, concentration of sulphuric acid
and to apparatus used for this purpose. The usual mode of concentration is to
evaporate the chamber acid in lead pans to a specific gravity of 1.750; afterwards
it is run into glass retorts placed in iron pots, with a layer of sand under-
neath under which fire places are fixed.
The acid is then boiled until it
attains the specific gravity desired, the weak acid vapours being withdrawn by
means of glass elbows placed on the neck of the retort, and conducted by
means of pipes to a condenser. When the acid is sufficiently concentrated
the fires are withdrawn, and the acid allowed to cool for about 12 hours.
The acid is then drawn off by means of lead syphons and conducted to coolers.
The object of my improvements is to render the process continuous without the
use of pots, syphons, condensers &c. In the first place I get retorts made of glass,
or any other suitable material, which are cylindrical, oval, or any desired shape,
with inlet and outlet apertures on the sides, or ends of retorts, which apertures are
sufficiently large to allow the volume of weak vapour in boiling to pass from the
lowest retort through the series and fr in thence to the chimney. I prefer to
use 5 or 6 retorts, each raised above the other so as to allow the acid to run from
the highest retort to the lowest. The retorts rest on tripods with a layer of sand
between, the same being placed behind a set of fire places by means mentioned
hereafter. The acid is run from the lead evaporating pans into the first retort
-

page_text: through the aperture on the side, and conducted from thence, by means of a
projecting tube on the opposite side about 3 inches below the inlet, on which
tube an adapter is fixed and conducted through the aperture on the side of the
second retort, the same arrangement being repeated through the whole series
The acid is run from the last retort in a concentrated form into coolers in which I
place a glass globe with a long neck graduated according to the specific gravity
required Attached to the globe is a lever connected by means of copper wire to a
glass plug adapted to regulate the supply of acid to the first retort from a vessel
placed between the evaporating pan and the retort. By this means the acid can
be regulated by the specific gravity of the acid in the cooler.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Samuel Bowen Bowen in the Great Seal Patent Office on the
17th October 1883.
SAMUEL BOWEN BOWEN of Llanelly in the County of Carmarthen
" IMPROVE-
MENTS IN THE MODE OF CONCENTRATING SULPHURIC ACID AND IN APPARATUS FOR
THE SAME
"
This invention relates to an improved form of Glass Retorts and connections, and
improved mode of concentration of sulphuric acid. The usual inode of concentration
is to evaporate the chamber acid, in leaden pans to a specific gravity 1-750;
afterwards it is run by means of pipes into glass retorts, placed in iron pots with a
layer of sand between, under which fire-places are fixed. The acid is then boiled
until the desired specific gravity is attained, the weak acid vapour being withdrawn
by means of glass connections placed on the neck of each retort, and conducted by
means of leaden pipes, to a lead condenser. When the acid is sufficiently con-
centrated, the fires are withdrawn, and allowed to cool for about 12 hours, the
concentrated acid is then withdrawn, by means of syphons and conducted to
coolers; by this means the operation becomes expensive in fuel, labour, and
material.
Now by my improved process the operation becomes a continuous one, and pots,
lead syphons, and condensers &c are dispensed with. In the first place I get a
series of retorts made of glass or any other suitable material, which are of a
globular, oval, the ordinary or any desired shape with inlet and outlet passages, on
the sides or ends of each retort, the same being made sufficiently large to allow
the volume of weak vapour to pass from the lowest retort through the series and
also serving to conduct the acid from the highest to the lowest retort by means of
glass tubes or adapters (as shown in drawing) connected to each retort, the weak
vapour ultimately passes through a small condenser, to the chimney.
By the vapour passing through the series, the more dense vapour of the lower
retorts, becomes condensed as it passes through the space of the adjoining retorts-
so that when it leaves the last retort it is in a very weak state.
For the series of retorts I suggest the use of 5 or 6 retorts, each retort being
raised above the other so as to allow the acid to run from the higheat retort to the
lowest the retorts stand on tripods, with a layer of sand between which rest in a
cast iron pan about 30" square and 6" deep to which a pipe is connected, in case
of a breakage when these pans would save the acid from being lost. The pipes
may be conducted along the front of the work to a suitable receptacle for the
recovery of the acid.
The retorts are placed in chamber spaces, heated by fires underneath. The hot
acid of specific gravity 1.750 is run from the evaporating pan to a convenient
receptacle by means of a lead syphon with an earthenware tap attached, from this
receptacle the acid is run into the first retort by means of a glass syphon, regulated
by a glass plug which is attached to a balance as hereafter described, and from
thence the acid is conducted by means of a projecting tube attached to the side of
the retort, which is about 6 inches long and 3" diameter on which is fitted an
adapter, and conducted into the second retort through the aperture on the side and
so continued through the series of retorts.
The concentrated acid is then run from the last retort into a platinum or glass
cup which is suspended to a platinum wire and the same connected to a lever
nicely balanced having the extreme end, connected to the glass plug to regulate the
acid supply to the first retort as desired.

page_text: To counter balance the weight of the platinum or glass cup of acid a weight is
placed on the opposite side of the balanced lever.
The lever or beam should be carefully balanced at the desired specific gravity
once this is done it will be self regulating according to the strength of the acid in
the cup.
All the necks of the retorts are closed by means of glass covers, excepting the
.first on which the connector placed, to carry off the weak vapour to the
-condenser, and from thence to the chimney.
:
.
Fig 1 represents a view in cross section of glass retort a resting on a tripod b
supported on and in a pan c to which a pipe d is connected for carrying off any
acid that may be spilled through breakage, to a suitable vessel; the pan c rests on
an archway el over the fireplace e" the flames of which pass through flue f into the
chamber space g and through side flues h in the front, into the main flue i, and
from thence to the chimney, j represents the opening on the side of retorts.
Fig 2 a part sectional and perspective elevation showing an evaporating pan a
from which the acid is drawn into a receptacle, b by means of a leaden syphon c on
which is attached an earthenware tap, from this the acid is conducted into the
retort d by means of a glass syphon e with the two ends bent upwards the end in
the receptacle being of a bell-mouthed shape to admit a tapered glass plug f which
is suspended from the lever as shown, the inlet passage g and outlet projection
tube h are about 3" diameter the projection tube h being about 6" long with a fall
of 1" in the length, over the projection tube h an adapter i is placed to conduct
the acid into the second retort, which also serves to conduct the vapour through
the series for partial condensation. On the neck of the first retort a glass
connector j is placed to conduct the vapour to the pipe K which leads to the
condenser...
Fig 3 is a part sectional and perspective elevation being in continuation of
Fig 2 and shows a covered leaden pan a about 3 feet diameter 1 foot deep, placed
on supports in an outer tank b, the tank b being supplied with cold water, to cool
the acid that runs from the last retort into the platinum or glass cup c, which,
.contains about 1 quart of acid, which is suspended by platinum wire d and
connected to lever E overhead from the leaden pan a, the acid runs in a
continuous stream by means of the syphon f into the cooler g from which the acid
is tapped into, carboys by means of syphon h.
The lever overhead is attached to the beams of the roof and is accurately
balanced on two centres, one end being connected to the glass plug fand the other
to the platinum or glass cup in leaden pan a. To close the opening i in pan a, I
have a glass dome with a small hole on the top to admit of the wired to pass
through.
Having thus described the nature of my invention I would have it understood
that I do not limit myself to the exact arrangements herein described as the same
may be varied without departing from the nature of the invention, but I claim the
form of retort and the apparatus combined there with for facilitating the passage of
acid and fumes, from one retort to the other, and the mode of regulating the supply
of acid by a practically self-acting system substantially as described and
illustrated and for the purposes set forth.
In witness whereof I the said Samuel Bowen Bowen have hereunto set my
band and seal this sixteenth day of October A.D. 1883.