Improvements in the Manufacture of Sulphuric Anhydride.
Year: 1899

page_text: Date of Application, 13th Feb., 1899
Complete Specification Left, 4th Oct., 1899-Accepted, 9th Dec., 1899
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Sulphuric Anhydride.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by the Verein Chemischer Fabriken, of
Mannheim, in the German Empire) to be as follows:-
:-
From experiments made on a large scale with the process forming the subject
matter of my application for Letters Patent No. 1859 of the 26th January 1899
my foreign correspondents have found that the conversion of the sulphurous acid
(obtained in the course of combustion, or roasting, processes from sulphur pyrites,
blendes, or other substances containing sulphur, or from other sources) into
sulphuric anhydride, is considerably increased, if the gases which escape from a
roasting furnace in normal operation, containing say, from 6 to 8 per cent., by
volume, of sulphurous acid, be diluted with desiccated air, either when in the
reaction chamber, or before entering it.
In the case referred to for example, the roaster gases, containing, as assumed
from 6 to per cent. by volume of sulphurous acid, are diluted by admitting dry
air over the layer of material which is roasting and under, or within, the reaction
chamber, so as to form, for use in the reaction, a gas mixture containing from
2 to 3 per cent, by volume of sulphurous acid.
Care should be taken to heat the dry air, as otherwise, by reason of the con-
siderably increased air-supply, an objectionable depression of temperature is apt
to take place in the reaction chamber.
Uated this 19th dow of Wahumanu 1900.
JOHNSONS & WILLCOX,
47, Lincolns Inn Fields, London, W.C.,
Agents.
Improvements in the Manufacture of Sulphuric Anhydride.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by the Verein Chemischer Fabriken, of
Mannheim, in the German Empire) and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
-
From experiments made on a large scale with the process and apparatus accord-
ing to my application for Letters Patent No. 1859 of the 26th January 1899 my

page_text: foreign correspondents have found that the conversion of the sulphurous acid
(obtained in the course of combustion, or roasting processes from sulphur pyrites,
blendes, or other substances containing sulphur, or from other sources) into
sulphuric anhydride, is considerably increased, if the gases which escape from a
roasting furnace in normal operation, containing say, from 6 to 8 per cent. by
volume, of sulphuric acid, be diluted with desiccated air, either when in the
reaction chamber, or before entering it.
In the case referred to for example, the roaster gases, containing, as assumed
from 6 to 8 per cent. by volume of sulphurous acid, are diluted by admitting dry
air over the layer of material which is roasting and under, or within, the reaction
chamber, so as to form, for use in the reaction, a gas mixture containing from
2 to 3 per cent. by volume of sulphurous acid.
Care should be taken to heat the dry air, as otherwise, by reason of the con-
siderably increased air-supply, an objectionable depression of temperature is apt
to take place in the reaction chamber.
In the accompanying drawings I have illustrated apparatus constructed as
shewn in the Specification of my application for Letters Patent No. 1859
but with additions to enable the gases to be diluted with dried air as herein-
before described. From the pipe by which dried air is supplied to beneath the
pyrites burners as in the said Specification of my application 185999 in the
furnace shewn in Figures 1 and 2 I lead pipes into the said burners above the
pyrites as shewn at for into the space beneath the contact material as shown
at f and for into the chamber or chambers containing the contact material as
shewn at for into either any or all of these as required. In the furnace shewn
in Figs. 3, 4 and 5 I have shewn pipes ele by which dried air is led into the
chambers containing the contact material.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim
is:--
In the manufacture of sulphuric anhydride, by means of roasting furnaces of
the character hereinbefore referred to, supplying additional dried air (preferably
preheated) to the roasting, or to the reaction, chambers, or both, so as to dilute
the gases substantially as hereinbefore described.
JOHNSONS & WILLCOX,
47, Lincolns Inn Fields, London, W.C.,
Agents.
JOHNSONS & WILLCOX,
47, Lincolns Inn Fields, London, W.C.,
Agents.