IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID, AND IN APPARATUS TO BE EMPLOYED THEREIN.
Year: 1871

page_text: LETTERS PATENT to Henry Deacon, of Appleton House, Widnes,
in the County of Lancaster, Alkali Manufacturer, for the Inven-
tion of "IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID, AND IN
APPARATUS TO BE EMPLOYED THEREIN.'
Scaled the 6th June 1871, and dated the 20th March 1871.
PROVISIONAL SPECIFICATION left by the said Henry Deacon at the
Office of the Commissioners of Patents, with his Petition, on the
20th March 1871.
I, HENRY DEACON, of Appleton House, Widnes, in the County of
Lancaster, Alkali Manufacturer, do hereby declare the nature of my
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID
AND IN APPARATUS TO BE EMPLOYED THEREIN," to be as follows:-
This Invention relates to the production of sulphuric acid, and
consists in the employment of salts of copper, such for example, as the
sulphate in conjunction with sulphurous acid gas together with oxygen
or air, so that sulphuric acid may be produced.

page_text: In carrying out my Invention I impregnate bricks or pieces of burnt
clay with strong solution of sulphate of copper and dry them. With
such materials I fill columns or towers leaving interstices to permit
of the passage of gases and leaving in the first part of such apparatus
vertical openings over vacant spaces to permit of any dust descending
by such openings into the empty space beneath without impeding the
draft by accumulating in the interstices of the filling. I apply heat
to such filled apparatus either externally or by means of heated gases
passing through or by both methods, and through the heated mass
of impregnated bricks or pieces of burnt clay I pass heated mixtures
of sulphurous acid gas and oxygen in equivalent proportions with or
without superheated steam.
Sulphuric acid is formed in the apparatus and may be obtained or
condensed from the issuing gases in any convenient manner, and the
gases not condensed if still containing sulphurous or sulphuric acids
may be passed into and treated as usual in an ordinary sulphuric acid
chamber for the conversion of the sulphurous acid into sulphuric acid
originally present and subsequently formed in the gases as is well
understood.
I obtain sulphurous acid gas from any convenient source, as for
example, from burning pyrites.
The ability of any given piece of the apparatus above described to
convert any given quantity of sulphurous acid gas into sulphuric acid
will, under similar circumstances, as to temperature and mixture of
gases be in almost direct proportion to the velocity with which the
gases can be passed through it, that is to say, if an apparatus will
convert into sulphuric acid nine-tenths of the sulphurous acid contained
in any mixture of it with oxygen, then about nine-tenths of the whole
will still be converted, if a very much larger quantity of the same mixture
be passed at the same temperature through the same apparatus in the
same time, and therefore the passages for the gas and the material used
for filling the apparatus should present as large a surface as possible,
and the pieces, or fragments should be so formed or arranged as to leave
the interstices or gas passages as small as the pressure or power available
to move the gases through the apparatus will permit. Large passages
permitting less power or pressure to be used, but yielding smaller results,
unless the length of these passages, and therefore the proportion of
surface to interstice, be correspondingly increased.

page_text: When it is desirable to convert a large amount of sulphurous acid
into sulphuric acid in as small a space or apparatus as possible, I
construct the apparatus so as to resist the necessary pressure where
necessary, and use any well-known powerful machines to propel or
exhaust, or to propel and exhaust the gases so as to obtain a high rate
of velocity of such gases through the apparatus.
It will be observed that the capacity of the same piece of apparatus
to convert the same per-centage of increased volumes of sulphurous acid
and oxygen into sulphuric acid in the same time is just in proportion,
or nearly so, to the increased velocity of the passing current of gases.
And is also dependent upon the gases being previously heated and
upon the heat of the apparatus itself being duly maintained or regu-
lated, that is to say, upon the temperature at which the operation is
performed.
Sulphate of copper is a convenient chemical re-agent, but other
substances or mixtures of substances possessing the same kind of
chemical power may be used instead.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Deacon in the Great Seal Patent Office on
the 20th September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DEACON, of Appleton House, Widnes, in the County of Lancaster,
Alkali Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of March, in the
year of our Lord One thousand eight hundred and seventy-one, in the
34th year of Her reign, did, for Herself, Her heirs and successors,.
give and grant unto me, the said Henry Deacon, Her special license
that I, the said Henry Deacon, my executors, administrators, and
assigns, or such others as I, the said Henry Deacon, my executors,
administrators, or assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the

page_text: Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF SULPHURIC ACID AND IN APPARATUS TO BE EMPLOYED
THEREIN," upon the condition (amongst others) that I, the said Henry
Deacon, my executors or administrators, by an instrument in writing
under hand and seal, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of
the said Letters, Patent.
NOW KNOW YE, that I, the said Henry Deacon, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings
and to the letters and figures marked thereon, that is to say:-
My said Invention relates to the production of sulphuric acid, and
consists in the employment of salts of copper, such for example, as the
sulphate in conjunction with sulphurous acid gas together with oxygen-
or air so that sulphuric acid may be produced.
In carrying out my Invention I impregnate bricks or pieces of burnt
clay with strong solution of sulphate of copper and dry them. With
such materials I fill columns or towers, leaving interstices to permit of
the passage of gases, and leaving in the first part of such apparatus
vertical openings over vacant spaces to permit of any dust descending by
such openings into the empty space beneath without impeding the draft
by accumulating in the interstices of the filling. I apply heat to such
filled apparatus either externally or by means of heated gases passing
through or by both methods and through the heated mass of impregnated
bricks or pieces of burnt clay I pass heated mixtures of sulphurous
acid gas and oxygen in equivalent proportions with or without superheated
steam.
Sulphuric acid is formed in the apparatus and may be obtained or
condensed from the issuing gases in any convenient manner, and the
gases not condensed if still containing sulphurous or sulphuric acids may
be passed into and treated as usual in an ordinary sulphuric acid
chamber for the conversion of the sulphurous acid into sulphuric acid
originally present and subsequently formed in the gases, as is well
understood.

page_text: I obtain sulphurous acid gas from any convenient source as for example
from burning pyrites.
The ability of any given piece of the apparatus above described to
convert any given quantity of sulphurous acid gas into sulphuric acid
will, under similar circumstances, as to temperature and mixture of
gases be in almost direct proportion to the velocity with which the
gases can be passed through it, that is to say, if an apparatus will
convert into sulphuric acid 9/10ths of the sulphurous acid contained
in any mixture of it with oxygen then about 9/10th of the whole
will still be converted if a very much larger quantity of the same
mixture be passed at the same temperature through the same apparatus
in the same time, and therefore the passages, for the gas and the material
used for filling the apparatus should present as large a surface as
possible, and the pieces or fragments should be so formed or arranged
as to leave the interstices or gas passages as small as the pressure or
power available to move the gases through the apparatus will permit.
Large passages permitting less power or pressure to be used, but yielding
smaller results, unless the length of these passages, and therefore the
proportion of surface to interstice be correspondingly increased.
When it is desirable to convert a large amount of sulphurous acid
into sulphuric acid, in as small a space or apparatus as possible, I
construct the apparatus so as to resist the necessary pressure, and use.
any well-known powerful machines to propel, or exhaust, or to propel
and exhaust the gases so as to obtain a high rate of velocity of such
gases through the apparatus.
It will be observed that the capacity of the same piece of apparatus
to convert the same per-centage of increased volumes of sulphurous
acid and oxygen into sulphuric acid in the same time is just in pro-
portion, or nearly so, to the increased velocity of the passing current
of gases, and is also dependent upon the gases being previously heated
and upon the heat of the apparatus itself being duly maintained or
regulated, that is to say, upon the temperature at which the operation
is performed.
Sulphate of copper is a convenient chemical reagent, but other
substances or mixtures of substances possessing the same kind of
chemical power may be used instead.
And in order that my said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that

page_text: purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts
in all the Figures.
Figure 1 of my Drawings represents a longitudinal vertical section of
one form or arrangement of apparatus for carrying my Invention into
effect. Figure 2 is a sectional plan of the same taken along the line 1, 2,
and Figure 3 is an end elevation with one of the pyrites burners in
section.
A, A, A, are a series of ordinary pyrites burners evolving hot sul-
phurous acid mixed with hot air; B¹ to B¹ inclusive are a series of
columns or towers made of any suitable materials, as bricks, or part
iron and part bricks, in which columns the materials impregnated with
sulphate of copper or other compound or combinations possessing similar
properties forming a porous mass are placed, being supported therein
on iron or brick work to admit of the equal passage of gas throughout
the porous mass. Vertical passages are formed in the first one or
more of these columns (see Figure 2) to allow of the deposit of dust
from the gases. These vertical passages may be conveniently made by
using pipes of hard burnt clay, such as agricultural drain pipes im-
pregnated with sulphate of copper, or other compound or combination
possessing similar properties, the bores coinciding in as nearly vertical
and uniform passages as possible. The dust will fall into the space
below from which it can be withdrawn from time to time. The other
columns may be filled with pieces of hard burnt clay, either mere shreds,
or else spherical pieces like common clay marbles of about half an inch
diameter, but all impregnated with sulphate of copper or other com-
pound or combination possessing similar properties. These columns
may be surrounded with brickwork containing flues C, C, in connection
with a fire or fires D to impart or maintain the necessary heat. The
gases issuing from the apparatus by the outlet C will contain the
sulphuric acid, anhydrous if dry gases are used, hydrated if moisture be
present, and any unconverted sulphurous acid, nitrogen, or excess of
air. These acids may be used direct in any convenient manner or the
anhydrous, sulphuric acid may be converted into hydrated sulphuric
acid, and the hydrated sulphuric acid may be condensed in any con-
venient manner, and the sulphurous acid remaining may be converted
into sulphuric acid in the ordinary leaden chambers by the ordinary
process.

page_text: It must be remembered that the sulphuric acid as it issues from the
apparatus or towers B, B, B, is in the state of vapour, and that if quickly
cooled in the presence of vapour of water it easily assumes the state of
fog which is with difficulty condensed or caught. The formation of fog
may be avoided by avoiding the too sudden cooling of any part of the
gases, and by avoiding the introduction of cold currents of air or water
to the hot gases whilst containing vapour of sulphuric acid. The gases
may be moved throughout by the use of any suitable aspirator, I prefer
to draw rather than force them by pressure.
In making sulphuric acid according to my Invention the temperature
must not reach the point at which sulphate of copper begins to be
decomposed in a current of hot air, or the whole of the sulphurous acid
cannot be converted into sulphuric acid, for sulphuric acid itself is more
or less decomposed into sulphurous acid and oxygen by the action of
heat alone at high temperatures. Conversely, by the action of heat
alone, sulphurous acid and oxygen will unite in part and form some
sulphuric acid. The use of the sulphate of copper or other chemical
reagent of similar power is, at any given temperature, to promote and
increase the proportional formation of sulphuric acid, and to retard
and decrease its proportional decomposition, so that at any given tem-
perature, by the use of sulphate of copper or its chemical equivalent, a
greater proportional quantity of sulphurous acid shall be converted into
sulphuric acid, and that by the use of it in a suitable apparatus and in
combination with a sufficiently low temperature, practically, the whole
of the sulphurous acid shall be so converted.
As the success of my Invention depends, therefore, not only upon the
use of such a chemical reagent as sulphate of copper, but also upon
the temperature at which it is performed, I proceed to point out the
principles which must guide the manufacturer in regulating the tem-
perature, and which, if followed, will ensure success. As herein-before
stated, sulphurous acid and oxygen will unite at temperatures at which
sulphuric acid is decomposed, neither reaction being complete; that is
to say, there is a considerable range of temperatures at which, if a
mixture of sulphurous acid and oxygen be passed through such an
apparatus as herein described, more or less sulphuric acid will be formed,
and if vapour of sulphuric acid alone, or mixed with air, be passed,
through the same apparatus at the same temperature some of it will
be decomposed into sulphurous acid and oxygen. Now as the tem-

page_text: perature rises from any point at which sulphuric acid is both formed
and decomposed in the presence of sulphate of copper or other com-
pound, or combination possessing similar properties, both the power to
form sulphuric acid and the power to decompose it augment, but the
power to decompose it augments more rapidly than the power to form
it. Conversely, as the temperature under the same circumstances falls
from any point at which sulphuric acid is both formed and decomposed,
both powers diminish, but the power to decompose diminishes more
rapidly than the power to form.
For each piece of apparatus and tension of gases two points of
temperature may be considered:-First, at the lowest temperature the
weight of sulphuric acid formed in any given time in a cubic foot of
the porous material will be the smallest, but the weight of sulphuric
acid decomposed will be practically nothing; an extension of apparatus
under those conditions will therefore give the largest possible per-
centage yield of sulphuric acid. Secondly, at the opposite, and for this
purpose highest extremity of temperature, the sulphuric acid formed
will be practically nothing, and cannot be increased by extension of the
apparatus. At any point of temperature between these two extremes
these two forces of production and decomposition will come in equi-
librium, so to say, sulphuric acid will be made and decomposed at equal
rates, and no increase of apparatus will vary the result. This point of
equilibrium. varies with every tension or proportion of sulphurous acid
gas to oxygen, and with every temperature, that is to say, as the
temperature falls this point passes in a corresponding degree from the
point of practically complete decomposition to the point of practically
complete production. The point for the best production of sulphuric
acid lics below the point at which sulphate of copper begins to be
decomposed in a current of hot air; and above that at which tin melts,
and safety lies in working large apparatus at this low indicated tem-
perature, and with the largest practicable admixture of air (oxygen).
The manufacturer, therefore, must work at this low indicated tem-
perature, and increase the per-centage of sulphurous acid converted
into sulphuric acid by extending the length of the apparatus, or other-
wise arranging it so as to give each particle of the gas more opportunities
of coming into contact with the surface of the sulphate of copper at
temperatures at which sulphuric acid is not materially decomposed.
An increased proportion of air or oxygen gas in any active form in

page_text: excess of the equivalent proportions will also, ceteris paribus, increase
this per-centage, but it will require more fuel to heat the larger mass
of
gas and more power to propel it. If sufficient air does not accompany
the sulphurous acid from the pyrites burners more may be admitted
before the gases enter into the rest of the apparatus, but I prefer
first to heat such air to the desired temperature. Similarly, if using
steam, which may be admitted along with or instead of the extra
amount of air, I prefer that it also shall be superheated to the desired
temperature.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that I do not
claim the manufacture of sulphuric acid by the use of oxides or salts
of copper, or of chromium, or of manganese, or of iron, or of other
compounds or combinations possessing similar properties, when such
chemical reagents, or any mixtures thereof, are used at a red heat; nor
do I claim the manufacture of sulphuric acid by the use of the metal
platina or any of its salts; but what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein-before
in part recited Letters Patent is,-
First. The manufacture of sulphuric acid by the combinations and
arrangements substantially as herein described.
Secondly. The manufacture of sulphuric acid by the use of sulphate
of copper or other chemical reagent, or mixture of reagents, possessing
the same kind of chemical power at temperatures varying between
about that point at which sulphate of copper begins to be decomposed
in a current of hot air and about that point at which tin melts, so that
the sulphate of copper, if that salt be used, may continue and remain
as sulphate of copper.
In witness whereof, I, the said Henry Deacon, have to this my
Specification set my hand and seal, the Sixteenth day of Sep-
tember One thousand eight hundred and seventy-one.