IMPROVEMENTS IN CONCENTRATING AND EVAPORATING SULPHURIC ACID AND OTHER LIQUIDS, AND IN THE APPARATUS EMPLOYED THEREFOR."
Year: 1872

page_text: LETTERS PATENT to Hector Auguste Dufrené, of No. 10, Rue de la
Fidélité, Paris, Republic of France, and 4, South Street, Finsbury,
London, Civil Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN CONCENTRATING AND EVAPORATING SULPHURIC ACID AND
OTHER LIQUIDS, AND IN THE APPARATUS EMPLOYED THEREFOR."-A com-
munication from Messieurs Marie Joseph François Regis Faure
and Jacques Louis Kessler, residing at Clermont-Ferrand, in the
Republic of France.
Scaled the 17th January 1873, and dated the 24th July 1872.
PROVISIONAL SPECIFICATION left by the said Hector Auguste
Dufrené at the Office of the Commissioners of Patents, with his
Petition, on the 24th July 1872.
I, HECTOR AUGUSTE DUFRENÉ, of No. 10, Rue de la Fidélité,
5 Paris, Republic of France, and 4, South Street, Finsbury, London, Civil
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN CONCENTRATING and EvaPORATING SULPHURIC

page_text: ACID AND OTHER LIQUIDS, AND IN THE APPARATUS EMPLOYED THEREFor," to be as
follows, that is to say :--
To carry out the Invention communicated to mo I employ cisterns
made of earthenware or platinum heated by an open fire or other
means. I prefer disposing them one above the other, and work them
in an intermittent or continuous manner. The vapours are directed
either into a chamber made of lead or other material not acted on by
sulphuric acid, or by any other substance under evaporation. The
vapours are condensed and collected. I can also employ the condensed
vapours for the manufacture of various chemical products, such as
sulphate of iron, sulphate of zinc, or sulphate of alumina.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Hector Augusto Dufrené in the Great Seal Patent
Office on the 22nd January 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HECTOR
AUGUSTE DUFRENÉ, of No. 10, Rue de la Fidélité, Paris, Republic of
France, and, South Street, Finsbury, London, Civil Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Ifer
Letters Patent, bearing date the Twenty-fourth day of July, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, er heirs and successors, give
and grant unto me, the said Hector Auguste Dufrené, Her special licence
that I, the said Hector Auguste Dufrené, my exccutors, administrators,
and assigns, or such others as I, the said Hector Auguste Dufrené, 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 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 CONCENTRATING AND EVAPORATING SULPHURIC ACID AND OTHER LIQUIDS, AND IN
THE APPARATUS EMPLOYED THEREFOR,' a communication from Messieurs
Maric Joseph François Regis Faure and Jacques Louis Kessler, persons
resident at Clermont-Ferrand, in the Republic of France, upon the
"

page_text: condition (amongst others) that I, the said Hector Auguste Dufrené,
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 im-
mediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Hector Auguste Dufrené, 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 Drawing hereto
annexed, and to the figures and letters marked thercon, that is to
say :-
The Invention consists in an improved method and apparatus for
concentrating and evaporating sulphuric acid and other liquids.
To carry out the Invention communicated to me I employ simple
dishes, pans, or vessels in which the liquid to be concentrated is heated.
The vapours which are given off when they are of sufficient value, are
collected over the upper surface of the dishes and condensed or utilized
in various ways. This evaporation is particularly advantageous for the
manufacture of sulphuric acid, between fifty-eight degrees and sixty-six
degrees Beaumé, and when it is employed for completing its con-
centration before its introduction into an evaporating apparatus for
distillation; but the principal advantage of this Invention is that it
allows of collecting at the same time the vapours passing off from
the dishes or vessels. This result is obtained by dividing the ordinary
distilling apparatus into several parts, so as to reduce to very small
dimensions the surface to be heated.
The dishes or vessels are preferably made of platinum; but they
may be made of cast iron or of other materials, such as natural
silicious stones, porcelain, and glass, which will allow of the heating
of the sulphuric acid up to nearly its point of ebullition without its
being much acted upon by the acid. This Invention however has
chiefly for object the arrangement of the apparatus and not the
materials employed for constructing the same. Thus I employ heated
vessels, dishes, or pans to form the body of the still, and I replace
the other parts of the still by a chamber formed of commoner. materials

page_text: for conducting the vapours into an ordinary refrigerator, sometimes for
condensing and conveying them to the exterior to be utilized in various
ways, or discharged into the open air at option.
'
The dishes or vessels are worked separately or collectively like a
cascade, discharging the heated liquid from one to the other, as shown
at B, B, Figures 3, 4, and 5.
The dishes may be emptied in a continnous manner by an overflow or
intermittently, and they may be filled in a continuous manner or by
successive charges.
The heating may be effected by means of a naked fire for platinum
or cast iron; but it is preferably effected by the medium of plates of
iron when the vessels or pans are of glass or porcelain.
The vapours given off during the evaporating process may be con-
densed or used for industrial purposes. In this case they are caused to
pass into leaden chambers like those employed for the manufacture of
sulphuric acid, they can also be utilized for the manufacture of chemical
products by passing them over dross or scum of zinc, oxides of iron,
ammoniacal waters, oxides or carbonates of magnesia, aluminous and
barytic matters, phosphates, and other materials, for the purpose of
obtaining sulphates, superphosphates, and other industrial compounds
therefrom.
The vessels employed for collecting the vapours may be made of
various kinds of materials, such as natural stones not acted upon by
acids, volvic lava, grit stones, viz., vosgien grit stones, the trachytes,
certain quartzites, the domite, the porphyrics, certain schists or other
silicious stones, and natural or bituminized plaster may be employed in
their composition.
These vessels may also be made of pottery carths or glass, which aro
good conductors of such vapours.
The Drawing hereto annexed shews two apparatus, by which the
Invention communicated to me may be carried into practice.
Figure 1 represents in plan, and Figure 2 in vertical section on the
line E, F, of Figure 1, an illustration of a platinum vessel evaporating
under a chamber or arch II of volvic lava, or of other silicious stone, ¦
such as grit stone; ff, is a crown of sheet iron protected from the action '

page_text: A second furnace y permits of keeping the iron plates hot enough not
to condense the acid, and not to be affected thereby.
Another system of refrigerator is shown at R, G, W. It consists of a
platinum tube F, F, placed in a leaden tube cooled by a circulation of
cold water in an inverse direction to that of the liquid egressing. Near
to it is a large leaden refrigerator W, placed in a cold water vessel R,
terminated by a tube T raised in the shape of a swan's neck, for allowing
the cooling sufficiently of the acid, so that the bottle a', a', may be.at
once filled.
When the chamber is not large enough to allow the ambient air to
cool sufficiently, water is poured over it, which is brought in by the
canal N. This water runs along its sides into a gutter Z, circulating all
round it and passing off outside. is the grate of the furnace of the
basin A; E, door of the said furnace; C, C, smoke conduits; m, m, cast-
iron plates, on which rest the porcelain dishes B, B; b, b, leaden tubes
conducting the acid into the said dishes at the discharge opening of the
leaden vessels G, G; 4, air thermometer, surrounded partially with a
protecting leaden tube; S, S, leaden chamber, which covers the circum-
ference of the vessels, and rises to the level of the plates, m, m.
Having thus described the nature of the Invention communicated to
mc, and the manner of performing the same, what I claim is, the im-
proved method and apparatus for concentrating and evaporating sulphuric
acid and other liquids, as herein-before described and represented in the
accompanying Drawing.
In witness whereof, I, the said Hector Auguste Dufrené, have here-
unto set my hand and seal, this Eighteenth day of January,
One thousand eight hundred and seventy-three.