OBTAINING LIQUID ANHYDROUS SULPHUROUS ACID FROM FURNACE AND OTHER GASES
Year: 1885

page_text: COMPLETE SPECIFICATION
We, EMIL HANISCH and MAX SCHROEDER, Engineers in the Village of
Neumuhl-Hamborn near Oberhausen, in the Kingdom of Prussia do hereby declare
the nature of said invention for "OBTAINING LIQUID ANHYDROUS SULPHUROUS
ACID FROM FURNACE AND OTHER GASES," and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement
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Hitherto for the production of liquid sulphurous acid it has been customary to
utilise only such gases as consist mainly of sulphurous acid, and contain but small
quantities of other gaseous bodies
According to the process applied by the inventors liquid sulphurous acid may
also be obtained from gaseous mixtures which like the combustion gases of sulphur
in the air, or the roasting, or calcination gases of pyrites, zinc blende and other
sulphurous minerals contain only a small per centage of sulphurous acid and ale
mainly composed of other gaseous components This process may be divided into
the following single parts
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1 The production of watery SO solutions by conducting the aforesaid gaseous
mixtures against and in contact with a stream of cold water
2 The production of pure SO³ gases from the said watery solutions by heating
the same to boiling point by blowing steam therein or by other means, and
removing the steam by condensation and suitable means for the withdrawal of the
water
3 The carrying over of the SO* gases obtained in the aforesaid manner into the
liquid state by compression or refrigeration
The process is performed in the following manner reference being had to the
accompanying drawing in which Fig 1 is a sectional elevation and Fig 2 a plan of
the apparatus employed.
The gaseous mixture proceeding from the roasting or calcining furnace or other
place of production passes through the pipe a into the lower part of the absorbing
tower 6 charged with coke lumps, or fitted with lattice or net work or other
suitable material, in which tower a stream of cold water is kept continuously
falling in a shower like form The water thoroughly absorbs the sulphurous acid,
whilst the other gases which are not absorbed, in most cases nitrogen and
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page_text: oxygen-pass through the pipe o from the upper part of the tower The
watery SO solutions flow through the pipe d in a continuous stream into the
series of closed pans e made of sheet lead in which the said solutions during then
passage through are heated to boiling point or nearly so by means of a fire
underneath the pans. The SO gases evolved in the pans, pass through the pipe f
into a cooling worm g surrounded with cold water, and then for the purpose of
removing the last water vapours, are caused to pass through the pipe ŉ into the
vessel 2 charged with pieces of chloride of calcium or besprinkled with sulphuric
acid, and thence through the pipe k to the compression pump 7
The
The contents of water passed through the series of pans which flows off through
the pipe m, still always contain a certain quantity of sulphurous acid and must in
case a more complete removal of the acid is required be further subjected to a
special process For this purpose it is caused to assume the form of fine rain which
while falling is met by a stream of water steam This as shewn in the drawing-
18 effected in the vessel n fitted with lead wire network The steam enters through
the pipe o and the evolved gases are carried off through the pipe p and similarly pass
to the aforesaid cooling worm g The water condensed in g flows back again into the
vessel n and with the exhausted water is discharged through the pipe g
pressure within the apparatus is regulated by means of the taffeta bag r It is in
connection with the pipe k and takes up the excess gases, the working of the
compressing pump being regulated by the dimensions it may assume for the time
being The gases compressed by the pump pass through the pipe s to the cooling
worm t that they may give off the heat generated in the compressing operation
From the cooling worm t they pass in the form of liquid into the container u
whence the liquid sulphurous acid thus formed may be finally drawn off into
receptacles such as v for delivery and use The pipe w serves for the occasional
blowing off of the permanent gases (oxygen and nitrogen) which pass over in
small quantities with the water, these gases are conducted into the absorbing
tower b
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is
The process for obtaining liquid sulphurous acid from furnace roasting or
calcining gases, or sulphurous gases of combustion, or other similar gaseous
inixtures in the manner that the sulphurous acid is absorbed from the same by
water, and the pure sulphurous gases obtained from the resulting watery solutions
by evaporation by means of heat, transformed into the liquid form by compression
or condensation or both, substantially as described with reference to the
accompanying drawing