IMPROVE- MENTS IN THE METHOD OF ABSORBING AND. RENDERING AVAILABLE for MANUFACTURES THE SULPHURIC AND SULPHUROUS ACID CONTAINED IN FURNACE GASES AND OTHER GASES OR VAPOURS EVOLVED IN DIFFERENT PROCESSES OF MANUFACTURE
Year: 1881

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN THE METHOD OF ABSORBING AND. RENDERING AVAILABLE for
MANUFACTURES THE SULPHURIC AND SULPHUROUS ACID CONTAINED IN
FURNACE GASES AND OTHER GASES OR VAPOURS EVOLVED IN DIFFERENT
PROCESSES OF MANUFACTURE." A communication from abroad by Dr. Karl
near Goslar in the German Empire.
Sahnabal of Lautenthal
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 2nd May 1881.
CHARLES DENTON ABEL. of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. IMPROVEMENTS IN THE METHOD OF ABSORBING AND
RENDERING AVAILABLE FOR MANUFACTURES THE SULPHURIC AND SULPHUROUS
ACID CONTAINED IN FURNACE GASES AND OTHER GASES OR VAPOURS EVOLVED
IN DIFFERENT PROCESSES OF MANUFACTURE." [A communication from abroad by
Dr. Karl Schnabel, of Lautenthal, near Goslar, in the German Empire.]
According to the present Invention the sulphurous acid fumes are absorbed from
furnace and other gases by means of certain solid substances, which are then
subjected to heat in order, firstly, to drive off the sulphurous acid in a concentrated
form, to be collected and employed for any purpose; and, secondly, to regenerate
the body serving as the absorbing medium, so that it may be again employed for
that purpose.
The solid bodies employed for the purpose of this Invention are basic carbonate
of zinc, carbonate of zinc, basic sulphate of zinc, and porous oxide of zinc, which
latter may be rendered porous by admixture of a certain proportion of basic sulphate

page_text: These substances are employed in pieces or in powder, moistened with water,
and are charged into the absorbing chambers or spread in layers on perforated
trays or hurdles, through which the gases or fumes to be purified are then made to
pass by a draught or suction produced by chimmies, exhaust fans, or other means
The sulphurous acid is absorbed by these substances with great energy, combining
with the zinc oxide and the moisture to form sulphite of zinc with about 25 per
cent. of water.
This sulphite of zinc is a white fibrous crystalline substance, and is permanent in
the atmosphere so long as it is dry. In a moist atmosphere it is only slowly
converted into sulphate of zinc.
The sulphite of zinc becomes decomposed already at a moderate red heat,
forming oxide of zinc, sulphurous acid, and water. It is for this purpose heated in
muffle ovens or other suitable apparatus, and the escaping concentrated sulphurous
acid is employed either for the manufacture of sulphuric acid or anhydride, or of
sulphur, sulphates. sulphites, or hyposulphates, or of aqueous or liquid sulphurous
acid. The remaining porous zinc oxide is moistened and employed over again for
the above process. The absorption process and the heating may be conducted in
such a manner that a certain quantity of basic sulphate of zinc is always contained
in the sulphite. The former does not become decomposed at the heat employed.
but binds the sulphite together in porous lumps resembling pumice stone in
appearance, which are particularly well adapted for absorbing the gas.
absorbing medium regenerated as described will serve for an indefinite length of
time without loss of zinc oxide, and without losing its powers of absorption.
The
The apparatus employed for the absorption may consist in towers or a number
of boxes or chambers of any suitable material, which may be so connected that the
fresh gases are first brought in contact with the most exhausted absorbing substances
and the exhausted gases with the fresh substances.
According to another arrangement the absorbing medium, in the form of powder
may be beaten into clouds inside a closed chamber, through which the gases are
made to pass, and thus an intimate contact between the two be insured.
Any sulphuric acid contained in the gases or fumes is also absorbed, forming
solid sulphate of zinc, which may be utilised either for the manufacture of vitriol
or of sulphuric anhydride.
By the above described processes it is rendered possible to convert completely or
partially the dilute sulphurous acid vapours from furnace gases into concentrated
sulphuric acid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abel in the Great Seal Patent Office on the
24th October 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN THE METHOD OF ABSORBING AND
RENDERING AVAILABLE FOR MANUFACTURES THE SULPHURIC AND SULPHUROUS
ACID CONTAINED IN FURNACE GASES AND OTHER GASES OR VAPOURS EVOLVED
IN DIFFERENT PROCESSES OF MANUFACTURE. A communication from abroad by
"
Dr. Karl Schnabel, of Lautenthal, near Goslar, in the German Empire.
According to the present Invention the sulphurous acid fumes are absorbed from
furnace and other gases by means of certain solid substances, which are then
subjected to heat in order, firstly, to drive off the sulphurous acid in a concentrated
form, to be collected and employed for any purpose; and, secondly, to regenerate
the body serving as the absorbing medium, so that it may be again employed for
that purpose.
The solid bodies employed for the purpose of this Invention are basic carbonate
of zinc, carbonate of zinc, basic sulphate of zinc, and porous oxide of zinc, which
latter may be rendered porous by admixture of a certain proportion of basic
sulphate of zinc.
These substances are employed in pieces or in powder, moistened with water,
and are charged into the absorbing chambers, or spread in layers on perforated
trays or hurdles, through which the gases or fumes to be purified are then made to
pass by a draught or suction produced by chimnies, exhaust fans, or other means.
The sulphurous acid is absorbed by these substances with great energy, combining
with the zinc oxide and the moisture to form sulphite of zinc with about 25 per
cent, of water.
This sulphite of zine is a white fibrous crystalline substance, and is permanent
in the atmosphere so long as it is dry. In a moist atmosphere it is only slowly
converted into sulphate of zinc.
The sulphite of zinc becomes decomposed already at a moderate red heat, forming
oxide of zinc, sulphurous acid, and water. It is for this purpose heated in muffle
ovens or other suitable apparatus, and the escaping concentrated sulphurous acid
is employed either for the manufacture of sulphuric acid or anhydride,or of sulphur,
sulphates, sulphites, or hyposulphates, or of aqueous or liquid sulphurous acid. The
remaining porous zinc oxide is moistened, and employed over again for the above
process. The absorption process and the heating may be conducted in such a
manner that a certain quantity of basic sulphate of zinc is always contained in the
sulphite. The former does not become decomposed at the heat employed, but binds
the sulphite together in porous lumps resembling pumice stone in appearance, which
are particularly well adapted for absorbing the gas. The absorbing medium.
regenerated as described, will serve for an indefinite length of time without loss of
zinc oxide, and without losing its powers of absorption.
The apparatus employed for the absorption may consist in towers or a number of
boxes or chambers of any suitable material, which may be so connected that the
fresh gases are first brought in contact with the most exhausted absorbing substances
and the exhausted gases with the fresh substances.
According to another arrangement the absorbing medium in the form of powder
may be beaten into clouds inside a closed chamber, through which the gases are
nade to pass, and thus an intimate contact between the two be insured.
Any sulphuric acid contained in the gases or fumes is also absorbed, forming
solid sulphate of zinc, which may be utilised either for the manufacture of vitriol
r of sulphuric anhydride.

page_text: By the above described processes it is rendered possible to convert completely or
partially the dilute sulphurous acid vapours from furnace gases into concentrated
sulphuric acid.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed as communicated to me by my foreign correspondent,. I
claim,
First. The process substantially as herein described of absorbing and rendering
innoccuous sulphurous acid fumes contained in furnace gases and gases or vapours
resulting from manufactures, by converting the same into sulphite of zinc by means
of zinc oxide or carbonates, or sulphates of zinc.
Second. In combination with the process above referred to the process of heating
the sulphite of zinc so as to obtain concentrated sulphurous acid therefrom, and to
regenerate the absorbing medium, substantially as described.
In witness whereof. I, the said Charles Denton Abel, have hereunto set my
་
hand and seal, this Twenty fourth day of October, in the year of our
Lord One thousand eight hundred and eighty-one.
CHAS. D. ABEL. (L.S.)