Improvements in the Manufacture of Acid Sulphites.
Year: 1891

page_text: Date of Application, 1st Oct., 1891
Complete Specification Left, 25th June, 1982-Accepted, 80th July, 1892
complete specificatioI LEIL, GULUNG, 1000 Accepted, on July, lov
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Acid Sulphites.
ARTHUR BOAKE and FREDERICK GEORGE ADAIR ROBERTS, Manufacturing
Chemists, both of Clonskea Chemical Works, Stratford, Essex do hereby declare
the nature of this invention to be as follows :—
The purification of the sulphurous acid gas which is intended for the manufacture
of acid sulphite solutions and salts by first compressing the gas into liquid by any
of the well known methods and then allowing the gas to boil off & be conducted
to the base intended for combination. In this manner all impurities such as free
sulphur are left as a residue.
$
This process is especially applicable to the manufacture of bisulphite of lime
solution intended for the preservation of beer &c. in which any free sulphur is
most objectionable.
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Dated this 30th day of September 1891.
A. BOAKE.
F. G. ADAIR ROBERTS.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Acid Sulphites.
We, ARTHUR BOAKE and FREDERICK GEORGE ADAIR ROBERTS, Manu-
facturing Chemists, both of Clonskea Chemical Works, Stratford, Essex, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to the manufacture or preparation of acid sulphite solutions
in a specially pure state by removing all traces of sulphur from the sulphurous acid
gas employed, by compressing the gas into a closed vessel under a pressure of
about 45 lbs. to the square inch or until it obtains the liquid form. When sufficient
acid has been liquefied in this way, it is allowed to gently boil off from the closed
vessel through a suitable duct or pipe into a solution of alkali or a milk of lime
or other alkaline earth and the usual process of manufacture of acid sulphite
solutions carried through.
It is to be understood that, under this Patent, we limit our claim to the
purification of the sulphurous acid gas by compressing it into the liquid state
before, and for the purpose of, combining it with the bases enumerated above.
We have found from experience that in the ordinary process of manufacturing
sulphites, sulphurous acid gas carries over from the plant in which it is generated
minute particles of sulphur which resist the usual means of removal by washing,
and the sulphur so carried over forms an unstable compound with the lime, or
other base, which even in minute quantities affects the commercial value of the final
product, especially if it be intended for the purpose of preserving beer.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
The purification of sulphurous acid gas intended for the manufacture of acid
sulphite solutions by first condensing it into the liquid state by pressure as above

page_text: described and then allowing it to evaporate through a suitable channel or pipe into
the vessel containing the base with which it is to be combined.
Dated this 21st day of June 1892.
ARTHUR BOAKE.
F. G. ADAIR ROBERTS.