IMPROVEMENTS IN THE TREATMENT OF SULPHUROUS OXIDE IN THE MANUFACTURE OF SULPHUROUS ACID (H. SO2) SULPHITES OR BISULPHITES
Year: 1884

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DFFCIFICATION.
I HENRY ERNEST SCHOLEFIELD Collyhurst Chomical Works St Oswald Street
of Manchester, in the county of Lancaster, Manufacturing Chemist do hereby
declare the nature of my said invention for "IMPROVEMENTS IN THE TREATMENT
OF SULPHUROUS OXIDE IN THE MANUFACTURE OF SULPHUROUS ACID (H. SO₂)
SULPHITES OR BISULPHITES to be as follows:-
In the manufacture of sulphites and bisulphites it is desirable to have the
sulphurous anhydride under pressure. If this pressure exist in the retort there is
a liability to loss and accident, and the retorts cannot be made so cheaply as when
no pressure above that of the atmosphere is used.
•
If too pyrites burners are used it is difficult to scrub the gases or pass them
through purifiers without pressure. If on the other hand exhausting fans or pumps
be used, these are liable to corrosion and to get out of order besides being costly to
work. Now my invention consists mainly in drawing off the gas from the sulphur
burner or pyrites burner by means of injecting, apparatus whether. of steam or
air or in rare cases of some other gas which it may be desirable to mix with the
SO.. By this means I can get any desired pressure without the use of moving
parts or of initial pressure in the burner or retort. If pyrites be used I place a
scrubber or scrubbers or other purifier on the line of passage so as to extract the
arsenic or other impurity. As steam, if used instead of air, coming in contact with
the SO, would heat the latter to an extent that might be deleterious if not
otherwise cooled, I prefer before taking it to an absorber to pass it through a
condensing apparatus. I usually also place a small collecting chamber beyond the
condenser so as to collect the solution of sulphurous acid which forms in the
condenser. This solution can be used as sulphurous acid or utilized in the making
of sulphites or bisulphites..
:

page_text: I, HENRY ERNEST SCHOLEFIELD, of Collyhurst Chemical Works, St Oswald
Street, Manchester, in the County of Lancaster, Manufacturing Chemist, do hereby
declare the nature of my said invention for "IMPROVEMENTS IN THE TREATMENT
OF SULPHUROUS OXIDE IN THE MANUFACTURE OF SULPHUROUS ACID (H₂SO₂)
SULPHITES, OR BI-SULPHITES" and in what manner the same is to be performed,.
to be particularly described and ascertained in and by the following statement :-
In the manufacture of sulphites and bisulphites it is desirable to have the
sulphurous anhydride under pressure. If this pressure exist in the retort there is a
liability to loss and accident, and the retorts cannot be made so cheaply as when no
pressure above that of the atmosphere is used.
If, too, pyrites burners are used it is difficult to scrub the gases or pass them
through purifiers without pressure. If on the other hand exhausting fans or
pumps be used, these are liable to corrosion and to get out of order, besides being
costly to work. Now my invention consists mainly in drawing off the gas from
the sulphur burner or pyrites burner by means of injecting apparatus-whether of
steam or air, or in rare cases of some other gas which it may be desirable to mix
with the SO. By this means I can get any desired pressure without the use of
moving parts or of initial pressure in the burner or retort. "If pyrites be used
I place a scrubber or scrubbers or other purifier on the line of passage so as to
extract the arsenic or other impurity.
It is best described by aid of the accompanying drawings which show a section
of my apparatus for making bisulphite.
A is the pipe leading from the pyrites burners or other source of SO₂. B jet of
steam, air, or other gas as above described under pressure. C condenser or cooler
with the mixed steam or air and sulphurous acid passing through it by worm D.
E entrance for cold water. F exit for heated water. G small collecting chamber
and cock to let off condensed sulphurous acid. H pipe leading to absorbers II,
in these J is a perforated false bottom. The chambers I I¹ are filled with water to
which lime soda or other caustic alkali or alkaline earth is gradually added taking
care to have a constant excess of sulphurous acid. H¹ pipe leading from I to 1.
H' exit pipe for air and waste gas.
The mode of action is as follows-
The SO, propelled forward by the air or steam jet is forced at the required
pressure through coil D, here the steam if used is condensed, taking up some SO
and is run out at cock G, as aqueous sulphurous acid and the excess of heat is
removed. The remaining SO, passes through the absorbers and is absorbed by the
lime or other alkaline carbonate, oxide or hydrate. When I is saturated, it is
disconnected, I¹ being placed first in series, and a freshly filled absorber taking the
place previously occupied by I¹. Instead of two absorbers three or more can be
worked in series, or a high column can be used and the basic material fed in at the
top and extracted fully sulphited at the bottom-the gas as usual entering at or
near the bottom.
If sulphites are wanted no water is used but the gas is passed through or over
shallow layers of a suitable compound of the alkali or alkaline earth.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1st. The improvement in the manufacture of sulphite or bisulphite which consists
in forcing the SO, into the absorbers by means of a jet of gaseous matter, sub-
stantially as described.

page_text: 2nd. The improvement in the manufacture of sulphurous acid sulphites or
bisulphites, which consists in the application of a steam or air jet for the purpose
of forcing the SO, into the absorbers, and of a condenser or cooler placed between
said jet and the absorbers to cool and condense the steam and form an aqueous
solution of sulphurous acid, if steam be used, or to cool only in the case of air or
other gas.