IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR TREATING ACID SULPHATE OF SODA OR BISULPHATE OF SODA FOR INDUSTRIAL PURPOSES
Year: 1884

page_text: DIECIFICATION.
I FRANK WIRTH of the firm of Wirth and Company; Patent Solicitors at
Frankfort-on-the-Main in the Empire of Germany do hereby declare the nature
of the said invention for "IMPROVEMENTS IN THE METHOD OF AND APPARATUS
FOR TREATING ACID SULPHATE OF SODA OR BISULPHATE OF SODA FOR INDUSTRIAL
PURPOSES," to be as follows:-
This Invention relates to a process and apparatus for the better utilization of
acid sulphate (acid sulphate of soda) or bisulphate (bisulphate of soda) which is
prepared in considerable quantities as a bye product in the manufacture of nitric
acid, &c, and which possesses very little value, whereby Glauber salt and carbonic
acid are obtained.
The apparatus consists of a closed boiler shaped lead lined mixing vessel provided
with a dome and traversed by a shaft furnished with stirrers, and to which vessel
are connected by pipes leading down to the bottom of said vessel:-(1) A lead
lined cistern containing a concentrated solution of acid sulphate. (2) A second
cistern containing calcium carbonate or other carbonic acid compounds suspended
in water, these two cisterns being above the mixing vessel, and (3) A filter below
said vessel connected therewith by a bent pipe also leading down to the bottom
of the vessel. There are also connected by pipes to the dome of said vessel :-
(1) A vessel containing carbonic acid under six atmospheres pressure, and (2). A first
washer which in turn is connected to a second washer which in turn is connected
to a gasometer, the first washer and the gasometer tank being filled with a solution
of calcium chloride while the second washer is filled with lumps of fused calcium
chloride. The various connecting pipes can be closed by taps.
The manufacturing process is in itself a very simple one and easily under-
standable.
A sufficient quantity of concentrated solution of acid sulphate or bi-sulphate is
run from the first cistern into the mixing and agitating vessel through the

page_text: communicating pipe which is then closed. A sufficient quantity of water con-
taining calcium carbonate or other carbonic acid compound held in suspension is
injected from the second cistern through the connecting pipe, by means of a pump
into the solution contained in the mixing vessel and both liquids are thoroughly
mixed by means of the stirring apparatus. The free sulphuric acid contained in
the sulphate thereupon combines with the lime setting free the carbonic acid and
forming calcium sulphate. The carbonic acid passes through the pipes into the
first and second washers and thence into the gasometer and is here stored as
gaseous carbonic acid and can as such be utilized, or passes on through a pipe
leading from the gasometer to the carbonic acid vessel in which it can be liquified.
The liquid contained in the mixing vessel is forced out through the filter by
means of the carbonic acid stored under pressure in the carbonic acid vessel
separated from the sulphate of lime and then worked up for Glauber salt..
The apparatus is a continuous one and excludes the air.

page_text: Ꮖ
COMPLETE SPECIFICATION.
I, FRANK WIRTH of the firm of Wirth and. Company Patent Solicitors, at
Frankfort on the Main, in the empire of Germany do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE METHOD OF AND APPARATUS
FOR TREATING ACID SULPHATE OF SODA OR BISULPHATE OF SODA FOR INDUSTRIAL
PURPOSES" (a communication to me from abroad by Hermann Herberts, Manu-
facturer, a person resident at Barmen in the empire of Germany) 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 a process and apparatus for the better utilization of
acid sulphate (acid sulphate of soda) or bisulphate (bisulphate of soda) which is
produced in considerable quantities as a bye product in the manufacture of nitric
acid & and which possesses very little value, whereby Glauber salt and carbonic
acid are obtained.
Reference is to be had to the accompanying drawing forming part of this
specification which illustrates the apparatus employed.
This apparatus consists of a closed boiler-shaped lead lined mixing vessel A
provided with a dome j and traversed by a shaft furnished with stirrers R and to
which vessel are respectively connected by pipes a and h leading down to the
bottom of said vessel: -(1) A. lead lined cistern B containing a concentrated
solution of acid sulphate. (2) A second cistern C containing calcium carbonate
or other carbonic acid compounds suspended in water, these two cisterns being
above the mixing vessel A. A filter H below said. vessel A is also connected
there with by a bent pipe g also leading down to the bottom of the vessel A.
There are also connected by pipes bc to the dome j of said vessel :-(1) A vessel D
containing carbonic acid under six atmospheres pressure, and (2) A first washer F
which in turn is connected by pipe d to a second washer G which in turn is
connected by a pipe e to a gas holder E, the first washer F and the gas
holder tank being filled with a solution of calcium chloride while the second
washer G is filled with lumps of fused calcium chloride. The carbonic acid
contained in the gasholder can be drawn off through a pipe f for further utilization.
The connecting pipes ab f g and h can be closed by stopcocks.
The manufacturing process is in itself a very simple one and easily under-
standable.
A sufficient quantity of concentrated solution of acid sulphate or bisulphate is
run from the cistern B into the vessel A through the pipe a which is then closed.
A sufficient quantity of water containing calcium carbonate or other carbonic acid
compound held in suspension is injected from the cistern C through the pipe h, by
means of a pump into the solution contained in the vessel A and both liquids are
thoroughly mixed by means of the stirring apparatus. The free sulphuric acid
contained in the sulphate thereupon combines with the lime, setting free the
carbonic acid and forming calcium sulphate. The carbonic acid passes through
the pipes c and d into the washers F and G and thence into the gasholder E, and
is here stored as gaseous carbonic acid and can as such be utilized, or it passes on
through a pipe fto the carbonic acid vessel D in which it can be liquefied.
The liquid contained in the vessel A is forced out through the filter H by means
of the carbonic acid stored under pressure in the vessel D, separated from the
sulphate of lime and then worked up for Glauber salt.
The apparatus is a continuous one and excludes the air,

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
The herein described method of treating sulphate of soda or bisulphate of soda,
without access of air, with calcium carbonate or other carbonic acid compounds,
whereby crystallized or calcined Glauber salt as also gaseous or liquid carbonic acid
are obtained, and by means of the apparatus consisting of a mixing and agitating
vessel A the cistern C the carbonic acid vessel D the washers F and G the gas-
holder E and the filter H, the said parts being connected together by pipes a, b,
d e, f, g furnished with stopcocks substantially as specified.