Im- PROVEMENTS IN THE CONSTRUCTION OF APPARATUSES FOR THE CONCENTRATION OF SULPHURIC ACID
Year: 1875

page_text: LETTERS PATENT to Albert Sauvée, of 22, Parliament Street, in the
County of Middlesex, Civil Engineer, for the Invention of "Im-
PROVEMENTS IN THE CONSTRUCTION OF APPARATUSES FOR THE CONCENTRATION OF
SULPHURIC ACID."-A communication from abroad by Marie Joseph
François Regis Faure, and Jacques Louis Kessler, both of Clermont
Ferrand, in the Republic of France.

page_text: in the joint when the ebullition becomes suddenly tumultuous. Several
reasons could be given to explain these phenomena, the removal of
which is part of the subject of this Invention. These defects are over-
como in the following manner:—
1st. By keeping the hydraulic joint at such a low temperature that its
contents can never boil.
2nd. By simply keeping the two metals close together and applying
to the joint thus made a suction from the inside of the apparatus.
Figs. 1, 2, & 3 (Plate 1), show one method of making a hydraulic
joint with a circulation of cold water for cooling the liquid. The cold
water enters through the tube b, and is discharged through the tube e.
It is compelled to circulate round the joint by means of the partition c,
and thus keeps the acid liquid in the joint from boiling. In this case it
is only the part f that is cooled, but if the cold water is applied on the
part of the gutter, it will give an equally good result. The cooling
of the joint may be effected by any other suitable means.
Figs. 1 & 3 show a separation between the liquid in the joint, and that
which is in the part n, which results from the condensation on the inside
of the apparatus. This separation may be dispensed with by boring a
hole through ƒ level with the bottom of the liquid, so that the two may
mix and run off through the same outlet. But the separation gives a
better cooling as the liquid in the joint does not receive a constant hot
supply.
Fig. 4 (Plate 1) shows a suction joint. The suction produced on the
joint between the two metals, lead and platinum, keeps in the acid
vapours, as they are constantly brought away by the indraught. If
these vapours are conducted to a well built refrigerator or still better
to the leaden chambers there is no loss of acid. The suction or indraught
may be produced by means of a steam jet in the outlet pipe, a chimney,
the draught in the leaden chambers when the vapours are conducted
there, or by any other suitable means. It is advisable to keep a small
quantity of acid under the brim i of the platinum pan as shown in
Figs. 1, 2, & 3, without letting the edge of the pan dip into it, but it
is not absolutely necessary to keep the edge dry whether it is cooled or
not.

page_text: can be a part of the platinum pan itself, as shown in Fig. 5 (Plate 1),
which represents one of the many combinations of cooled hydraulic
joints. The liquid fills the gutter m, but if the edge spout o is lowered
to p, there is no liquid left in the gutter, and by producing an indraught
this joint becomes a suction joint.
The hydraulic joint is described above as a joint with liquid, but it is
evident that if this liquid is thickened more or less, the main points of
the joint will not be altered. To thicken the liquid, white lead, sulphate
of barytes, silicium, or any other material not attacked by sulphuric
acid may be used. If the liquid is rather thick the joint as shown in
Fig. 5 still remains a hydraulic joint, even if the spout o be lowered
to p. A thick substance like putty might be used.
Fig. 6 (Plate 1) shows a complete apparatus provided with the
hydraulic joint. The cover of the platinum pan is made in two parts,
one inside the other with a circulation of water between them to keep
them cool. But if the cover is made of earthenware with an outer
jacket of lead, it is not necessary to cool it by water. It may be made
of lava or any other material not liable to be attacked by the acid.
The two systems of joints herein-before described may be used with a
cover made of platinum, and consequently with the top part of the
ordinary platinum still for concentrating sulphuric acid.
I will now proceed to describe the second part of this Invention, viz.,
the various improvements in the construction of the refrigerators for
cooling the concentrated sulphuric acid. These refrigerators are built
by the Inventors, either nearly entirely of lead or of a special earthern-
ware, and so as to more clearly describe the two systems, I have divided
the description into two sections.
1st. Leaden refrigerators. The use of lead in the construction instead
of platinum is based upon the fact that sulphuric acid even when
concentrated does not attack lead when the temperature of the acid is
only about 212° Fah.
The leaden refrigerator is composed of two distinct compartments; in
the first, care is taken to keep a certain quantity of cooled acid at
about 212°, and the hot acid is brought in from the concentrating
apparatus or still, in such a manner as to be mixed at once on its arrival
with the cold acid, therefore the acid does not come in contact with the

page_text: lead of the refrigerator at a temperature sufficiently high to attack it.
The cooling of the acid is completed in the second compartment, which
is not liable to be attacked.
Plate 2 shows two arrangements of leaden refrigerators; Fig. 1 is a
vertical section through the axis of a tubular refrigerator; Fig. 2 is the
quarter of a horizontal section of same, showing the leaden tubes
through which the cold water circulates, and around which is the acid;
the hot acid arrives in the first compartment A through the tube a made
of platinum, lava, earthenware, or other suitable material, and strikes
against two porcelain saucers or a layer of quartz shingle. On account
of its high temperature, and therefore its light specific gravity, the hot
acid rises vertically through the cooler acid and mixes with it, thus
lowering the temperature of the hot acid to below 212°. The cold water
passing through the tubes c, c, keeps the temperature low. This
water is brought through the pipe d to a reservoir at the bottom of the
refrigerator, into which all the tubes c, c, open; passing through
these it rises into an annular chamber from whence it escapes through
the outlet pipe f. The acid falls into the lower compartment B where
it loses its remaining heat, and is drawn off through the tube t; Figs.
3 & 4 show the second arrangement of leaden refrigerator, which may
be called an annular refrigerator; Fig. 3 is a vertical section through A, B,
and Fig. 4 shows the top of the apparatus. The acid arrives in the
same manner as in the last instance through the tube z, and mixes with
the partly cooled acid in compartment C; from there it passes into the
annular compartment D, and is drawn off through the pipe u, which
is itself placed inside the pipe which brings the cold water to the
compartment F.
2nd. Earthernware refrigerators. The Inventors have succeeded in
using earthernware for the construction of refrigerators.
1st. By providing against the chances of breakage in protecting the
first jars in which the hot acid arrives with a leaden jacket cooled with
water.

page_text: be made on the principle of the hydraulic joint. If colourless acid is
required, the jar is made of very thick earthernware, and it may be
covered outside with lute or sand. The lute may be made of clay,
silicate of sodium, plaster of Paris, sulphate of barium, or any other
substance that resists the action of hot sulphuric acid. This lute is kept
on the jar by means of a leaden jacket, and the whole is put in a tub
lined with lead and full of water, as shown at ƒ, ƒ. The funnel and the
cover are soldered to the jacket. The acid passes from this jar through
a glass or earthernware syphon into a series of cylindrical earthernware
pots e, e, e, also jacketted with lead, and grouped together in a tank 1, l,
lined with lead and full of cold water. The edge of the leaden jacket
round each pot is soldered at the top to a kind of tubular leaden plate
which closes the tank. On the edge of the tank itself, there is a leaden
gutter, into which the pyramid shaped cover g, g, drops, so as to form a
hydraulic joint.
In the pyramid-shaped cover there is a trap h with hydraulic joint,
which allow the inspection of the pots and the syphons which establish
the communication between them. The holes in the cover through
which the syphons pass are packed with abestos. The number of the
jars or pots is so calculated, that when the acid leaves the tank 1, 1, it
does not give off fumes, and then a series of uncovered pots is sufficient
to complete the cooling.
The Drawing (Plate 3) shows a jar and a tank with pots, but the
refrigerator can be composed of jars only, or of pots in tanks only.
Instead of earthernware, porcelain, lava, or any other material not:
attacked by hot sulphuric acid may be used.
In witness whereof, I, the said Albert Sauvée, have hereunto set
my hand and scal, this Seventeenth day of August, in the year of
our Lord One thousand eight hundred and seventy-five.