RESERVE Pressure with Agitation and in Apparatus for that Purpose.
Year: 1886

page_text: Date of Application, 9th Nov., 1886.
Complete Left, 21st July, 1887.
Complete Accepted, 30th Aug., 1887.
RESERVE
Pressure with Agitation and in Apparatus for that Purpose.
1 WILLIAM BURNS of 32 Elmwood Terrace Leith in the County of Mid-Lothian,
Consulting Engineer and Chemist, do hereby declare the nature of my said invention
for IMPROVEMENTS IN THE MANUFACTURE OF SULPHURIC ACID UNDER
PRESSURE WITH AGITATION; AND IN APPARATUS FOR THAT
follows:-
HIGH
PURPOSE to be as
I employ a novel combination of apparatus to cause the chemical combination of
sulphur and oxygen under high prossure and form sulphuric acid of any required
strength at one operation, The usual method of making sulphuric acid is to burn
sulphur in a curront of atmospheric air to form sulphurous acid, and inject the
sulphurous acid and atmospheric air; along with nitrous acid into large leaden
chambers containing water and steam, where these acids slowly combine and form
sulphuric acid of low specific gravity, which requires to be further concentrated by
boiling in glass or platinum vessels which is a tedious and expensive process, By my
invention the aforesaid gases can be made to combine under high pressure with
agitation and form sulphuric acid much quicker at one operation, and of any required
strength in steam tight cylinders, To accomplish the above purpose, I use an iron
retort lined with fire brick and provided with gas tight lids at top and bottom, in
which I burn sulphur to form sulphurous acid, by blowing atmospheric air into the
retort by a blowing machine, the retort may be kept at the required temperature by a
fire under it to cause combination of the oxygen of the air with the sulphur and form
sulphurous acid, or the sulphur may be first fired inside the retort and then the doors
closed and a blast of air turned on.
The sulphurous acid formed in the retort is forced along a pipe where it meets and
mixes with. nitrous acid gas obtained from the decomposition of nitrate of soda. These
mixed gases are then forced through a condensing syphon where they are cooled und
deposit any sublimed sulphur that may be driven over by the heat of the retort,
When the gases reach the exit end of the syphon they are mixed with the requisite
quantity of atmospheric air to supply an equivalent of oxygen to the sulphurous acid

page_text: to convert it into sulphuric acid, These gases are then forced through a novel vessel
called the mixer, hereafter described where they meet with a jet of high pressure steam
which thoroughly mixes the gases in a basin, the mixed gases and steam when they
leave the mixer pass over the surface of sulphuric acid contained in a basin inside an
air tight cylinder where combination of the greater part of the sulphurous acid and
oxygen takes place and along with the steam forms oil of vitriol, which is collected
in the bottom of the cylinders.
The uncombined portion of the gases are forced up through a series of cup and ball
agitators hereafter described where a further combination takes place. After the
whole of the sulphurous acid has been absorbed the remainder of the gases are forced
along with an additional portion of atmospheric air through another cylinder
containing cup and ball agitators and filled with ammoniacal liquor or a solution of
soda. The nitrous gases in passing through the ammoniacal liquor combine with the
ammonia and form nitrate of ammonia; or if soda is used nitrate of soda is formed,
which can be used over again without incuring any loss. Any number of cylinders
and agitators can be used, according to the quickness with which it is required to
.work, If it is required to work slowly and make strong acid one cylinder and one
set of agitators will be sufficient, but if it is required to work rapidly and make acid
of different strengths the number of cylinders and agitators must be increased in
proportion to the quantity and strength of acid required in a given time, The
combining cylinders may be made of cast iron or boiler plate of sufficient strength to
sustain a working pressure of from 3 to 4 atmospheres, and may be lined inside with
lead glass, or stone ware, If strong acid is required they should be lined with glass
or stone ware, if weak acid is required they may be lined with lead, The great
advantage of the above system of making sulphuric acid is,
First-It does away with the necessity of large and troublesome leaden chambers.
Second-Acid of any required strength can be made at one operation by limiting
the quantity of steam to the required strength; and no further concentration is
required.
Third The whole of the nitric acid is recovered in the form of nitrate of aminonia
or nitrate of soda without the necessity for expensive "Glover Towers."
The higher the pressure at which the gases are forced into the cylinders the quicker
the combination takes place, and a smaller quantity of nitric acid is required, a
pressure of half an atmosphere gives good results.
Referring to the drawings on sheet A which shew a vertical section of a single
cylinder apparatus for the manufacture of sulphuric acid according to the foregoing
description.
A is a cylindrical retort for burning sulphur, C is a retort for distilling nitre, these
retorts are placed horizontally in an oven with a fire F, under them, and R is a vessel
for holding acid sulphuric. The mixer M is a cylindrical vessel made of cast iron
lined with lead or enamel inside, and provided with an inverted cone having the nozzle
dipping into the basin J, fixed near the bottom of the vessel as shewn in section,
The basin should be made of strong glass or stone-ware and the nozzle of cone should
be made smaller in diameter than the inlet pipes, so as to cause the gases to pass
through it with increased velocity. In operating with the above described apparatus
1 fill the retort A with sulphur; and U with nitrate of soda, and I fill R with
sulphuric acid, then kindle a fire in the furnace F, and as soon as the retorts are
brought to a proper heat I inject a blast of air into the retort A through the perforated
pipe Q, from a blowing engine. The oxygen of the air unites with the sulphur and
forms sulphurous acid; at the same time I turn a small stream of sulphuric acid from
the vessel R into the nitre retort C, the sulphuric acid decomposes the nitre and
liberates the nitric acid which passes up the pipe H into the mixer M, in the state of
vapour. The sulphurous acid from the retort A passes up the pipe D and down the
pipe D into the vessel G, then up the pipe D and into the mixer M, at the same
time I force atmospheric air into the mixer M, from a blowing engine through the
pipe P, and also a blast of high pressure steam from a boiler through the pipe S. The
sulphurous acid in pussing through the pipes D' D" is cooled by the external air and

page_text: deposits the sublimed sulphur in the vessel G, which can be removed by the door a.
The aforesaid gases and steam that enter M, are forced through the nozzle of the cone
into the basin J and strike on the bottom of the basin with force which causes a
thorough mixture of the gases, and brings the molecules into what may be called
combining contact. The gases and steam on leaving the mixer enter the large
cylinder ; at the point I, where they are deflected by the glass plate I down upon
the surface of the sulphuric acid contained in the basin L, where the greater portion
of the oxygen and sulphurous acid in passing over the surface of the sulphuric acid
and under the edge of the plate I, unite and form sulphuric acid, which falls to the
bottom of the cylinder. The uncombined gases ascend in the cylinder and pass through
the cup and ball agitators K K' where the remainder of the sulphurous acid is
converted into sulphuric acid and falls to the bottom.
Fig. 1 on sheet A shows a section of a portion of the cup and ball agitator on a
larger scale, Z, shews one of the balls forced up by the gas into the upper cup or bell, and
the arrows shew the direction the gases take in passing through the cups, The
constant rising and falling of the balls in the cups keeps up an agitation, among the
molecules which favours combination. Fig. II shews a plan of the soffit of a portion
of the upper cups or bells, these agitators should be made of glass or stoneware. The
remainder of the gases consisting of nitrogen and nitrous acid, pass out of the
cylinder E by the pipe N and are conveyed into the cylinder O, which should be filled
with ammoniacal liquor or a solution of soda, The gases are forced through the
liquor along with an additional portion of air which enters by the pipe B, the oxygen
of the air converts the nitrous acid into nitric acid, and in passing through liquor
converts it into a nitrate, the nitrogen gas escapes by the valve V and passes into
the air by the pipe U, A constant supply of liquor. is kept up from the cistern-T,
the liquor passes into the bottom of the cylinder O by the pipe X, where it unites
with the gases in passing through the cup and ball agitator K", The nitrate liquor
overflows by the valve V and falls down the pipe U into the evaporating pan W,
where, it is evaporated and crystalized and made fit to be used over again in the
nitre retort.
The operation can be carried on under any required pressure by weighting the
valve V to the pressure desired. The sulphuric acid is drawn from the cylinder E by
the valve Y at the bottom. In manufacuring on a large scale I prefer using three
combining cylinders similar to E, and a vertical retort for burning iron pyrites to
produce the sulphurous acid, which will be fully described in the complete
specification.
Dated this 10th dose of December 1886

page_text: Pressure with Agitation and in Apparatus for that Purpose.
I WILLIAM BURNS of 32 Elmwood Terrace Leith in the County of Mid-Lothian
Consulting Engineer and Chemist, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
I employ a novel combination of apparatus to cause the chemical combination
of sulphur and oxygen under high pressure, and form sulphuric acid of any required
strength at one operation.
To accomplish the above object I employ a cast iron retort with gas tight lids, lined
with fire bricks or other refractory material. The retorts may be placed horizontally
or vertically, and may be heated either with an external or internal fire. Inside the
gas tight retort, I burn sulphur or iron pyrites, to produce sulphurous acid, by blowing
atmospheric air into the retort by a blowing machine, the retort may be kept at the
required heat by external fire under it or the sulphur may be first fired inside the
rétort and then the doors closed, and a blast of air turned on. I fix a second retort
inside the pyrites retort in which I decompose nitrate of soda to produce nitrous gas
which I cause to be mixed with sulphurous acid, air, and steam, in a combining
cylinder under high pressure. The sulphurous acid formed in the retort is forced along
a pipe where it meets and mixes with nitrous acid gas obtained by the decomposition
of nitrate of soda, These mixed gases are then forced through a condensing syphon
where they are cooled and deposite any sublimed sulphur that may be driven off by
the heat of the retort When the gases reach the exit end of the syphon they are
mixed with the requisite quantity of atmospheric air to supply an equivalent of oxygen
to the sulphurous acid, to convert it into sulphuric acid. These gases are then forced
through a novel vessel called a mixer, hereafter described, where they meet with a jet
of high pressure steam which thoroughly mixes the gases in a basin, the mixed gases
and steam when they lave the mixer pass over the surface of sulphuric acid contained
in a basin inside an air tight cylinder where combination of the greater part of the
sulphurous acid and oxygen rapidly takes place, and along with steam forms oil of
vitriol, which is collected in the bottom of the cylinder. The uncondensed portion of the
gases are forced up through a series of cup and hall agitators hereafter described,
where a further combination takes place; after the whole of the sulphurous acid has
been absorbed the remainder of the gases are forced along with an additional portion
of atmospheric air though another cylinder containing cup and ball agitators, and
filled with ammoniacal liquor or a solution of soda, The nitrous gases and air in
passing through the ammoniacal liquor combine with the ammonia and form nitrate
of ammonia or if soda is used nitrate of soda is formed which can be used over again
in making nitrous acid without incuring any. loss.

page_text: Any number of cylinders and agitators can be used according to the quickness with
which it is required to work, If it is desired to work slowly and make strong acid,
one cylinder, and one set of agitators will be sufficient, but if it is required to work
rapidly and make acid of different strengths the number of cylinders and agitators
must be increased in proportion to the quantity and strength of acid required within
a given time, The combining cylinders may be made of cast iron, boiler plate or
other metal of sufficient strength to sustain a working pressure of 3, to 4, atmospheres,
and may be lined with lead, glass, or stone ware, If strong acid is required to be
made the cylinders should be lined with glass or stomeware, If weak acid only is
required they may be lined with lead. The great advantage of the above system of
making sulphuric acid is, First it does away with the necessity for the large and
troublesome leaden chambers, Second, acid of any required strength can be made
at one operation by limiting the quantity of steam to the required strength, no further
concentration is required. Third the whole of the nitric acid is recovered in the form
of nitrate of ammonia, or nitrate of soda, without the necessity of expensive "Glover
Towers." The higher the pressure at which the gases are forced into the cylinders,
the quicker the combination takes place, and a smaller quantity of nitric acid is
required, a pressure of half an atinosphere gaves good results.
Referring to the drawings on sheet A accompanying the provisional specification.
These drawings shew a vertical section of a single cylinder apparatus for manufacturing
sulphuric acid according to the foregoing description.
A is a cylindrical retort for burning sulphur, O is a retort for distilling nitre; these
retorts are placed horizonally in an oven with a fire F, under them; R, is a vessel
for holding sulphuric acid, Tho mixer M, is a cylindrical vessel made cast iron lined
with lead and provided with an inverted cone having the nozzel dipping into be
basin J, fixed on the bottom of the vessel as shown in section, the basin should be
made of strong glass or stone ware and the nozzle of the cone should be made
smaller in diameter than the inlet pipes, so as to cause the gases to pass through it
with increased velocity; and impinge on the bottom of the basin J. In operating
with the above described apparatus, I fill the retort A, with sulphur and C, with
nitrate of soda and I fill R, with sulphuric acid, I then kindle a fire in the furnace F,
and as soon as the retorts are brought to proper heat 1 inject a blast of air into
the retort A, through the perforated pipe Q, from a blowing engine.
The oxygen of the air unites with the sulphur and forms sulphurous acid, At
the same time I turn a small stream of sulphuric acid from the vessel R, into the
nitre retort C, the. sulphuric acid from the vessel R, decomposes the nitre and
liberates the nitric acid which passes up the pipe H, into the mixer M, in the state
of vapour, The sulphurous acid from the retort A, passes up the pipe D, and down
the pipe I, into the vessel G, then up the pipe D, and into the mixer M, at the
same time atmostheric air is forced from a blowing engine through the pipe P,
into M, and a blast of high pressure steam from a boiler is blown into M, through the
pipe S. The sulphurous acid in passing through the pipes D' D" is cooled by the
external air and depositos the sublimed sulphur in the vessel G, which can be removed
by the door a. The aforesaid gases and steam that entre M, are forced through the
nozzel of the cone into the basin J, and strike on the bottom of the basin with
considerable force which causes a thorough mixture of the gases and brings the
molecules into what may be called combining contact. The gases and steam, on
leaving the mixer enter the large cylinder E, at I, where they are deflected by the
glass plate I, down upon the surface of sulphuric acid contained in the basin L,
where the greater portion of the sulphurous acid and oxygen in passing over the
surface of the sulpliuric acid under the edge of the plate I, unite and form strong
sulphuric acid which overflows and falls to the bottom of the cylinder, The
uncombined gases ascend in the cylinder and pass through the cup and ball
agitators K, K, where the remainder of the sulphurous acid is converted into
sulphuric acid and falls to the bottom, Fig. I on sheet A, shews a section of a
portion of the cups and balls on a larger scale, Z shows one of the balls forced up by
the gas into the upper cup or bell, and the arrows show the direction the gases

page_text: take in passing through the cups, The constant rising and falling of the balls in
the cups keep up an agitation amoung the atoms, which facilitates combination. Fig. II
shews a plan of the soffit of a portion of the upper cups, The agitators should be
made of glass or stone-ware, The remainder of the gases consisting of nitrogen
and nitrous acid, pass out of the cylinder by the pipe N, and are conveyed into the
cylinder O, which should be filled with ammoniacal liquor or a solution of soda, The
gases are forced through the liquor along with an additional portion of atmospheric
air which enters by the pipe B, the oxygen of the air converts the nitrous acid into
nitric acid, and in passing through the liquor, converts it into nitrate, the nitrogen
escapes by the valve V and passes into the air by the pipe U.
A constant supply of liquor is kept up from the cistern T, the liquor passes into the
bottom of the cylinder, O, by the pipe X where it mixes with the gases in passing
through the cup and ball agitator K", The nitrate liquor overflows by the valve V,
and falls down the pipe U, into the evaporating pan W, where it is evaporated and
crystalzed and made fit to be used over again in the nitre retort. The operation can
be carried on under any required pressure by weighting the valve V to the required
pressure. The sulphuric acid is drawn from the cylinder E by the valve Y. In
manufacturing on a large scale I prefer using three combining cylinders and a vertical
retort for burning the iron pyrites, according to the following description, and plans
shewn on sheets B and C. Referring first to sheet B. Fig. I, is a part of the cup and
ball agitator already described. Fig. II, and III are vertical sections of pyrites
retorts and steam boiler, at right angles to each other. A, is the body of a cylindrical
retort lined with fire bricks for burning pyrites F, is a furnace grating b, a gas tight
door to the furnace, C, is the discharging tube with valve on bottom, e, is a steam
superheater built into the brickwork of the furnace, C, is a retort resting on a brick
arch, R, is a vessel for holding sulphuric acid, B, is a steam boiler with flue D, up
through the centre, D₁, is a jacketed pipe for condensing the sulphurous acid, G, is a
chamber for collecting sublimed sulphur, Sheet C, 1, 2, and 3 are combining
cylinders lined with glass, stone-ware or load, O is the nitrous acid absorber, and M,
is the gas mixer, These cylinders should be made capable of sustaining a pressure
of 3 or 4 atmospheres and if strong acid is required to be made they should be lined
with glass, or stone ware, fixed with a cement made of boiled pitch and china clay;
and if weak acid only is required they may be lined with lead. It is preferable to
line No. 1, cylinder, with stone ware, and No. 2, and 3 with lead. The mode of
operating with the apparatus is as follows I fill the retort A with pyrites through the
flue D, the pyrites in falling, strikes against the rib and cone A' which spreads the
pyrites equally over the retort and breaks the fall, I then fill the retort C with
nitrate of soda and fill the vessel R, and the basins L, L', L", in the combining
cylinders 1. 2. and 3 shewn on sheet C, with sulphuric acid, and I fill the vessel
with a saturated solution of soda, I then kindle a fire in the furnace F, and fix the
door b. I then blow air through the furnace grating F, by a blowing machine which
kindles the pyrites and producos sulphurous acid, which travels up the pipe D, and
down the pipe D¹, and along the chamber G, then up the pipe D, then enters the
mixer M. The sulphurous acid in its passage through the pipe D', is cooled by the
air from the blower as it travels through the pipe P1, the air cools the gas and causes
it to deposite the sublimed sulphur in the chamber G. and at the same time the hot
gas warms the air in its passage to the furnace.
The heat from the burning pyrites raises the steam in boiler B. which is lead down
the pipe S¹ into the superheater e, in the furnace, and then up the pipe S", and along
the pipe S, into the mixer M, As soon as the retort C has got up to the proper heat
which is known when the steam in the boiler B is freely produced, I lift the valve in
the vessel R and allow a stream of sulphuric acid to run into the retort C, the
sulphuric acid and heat from the burning pyrites dissolves and decomposes the nitrate
of soda, and the nitrous gases, rise up through the pipe H, and enter the mixer M,
along with the sulphurous acid and steam, As soon as the sulphurous acid, and steam
begin to enter the mixer M, I turn a blast of air on, through the pipe P, which enters
the mixer along with the sulphurous acid, nitrous gas, and steam (see sheet C) these

page_text: gases force their way through the nozzel of the cone and impinge on the bottom of
the basin J, which causes a thorough mixture of the gases, The mixed gases and
steam, then pass from the mixing basin into the combining cylinder No. 1 and are
caused by the spreader i to sweep over the surface of the sulphuric acid contained in
the vessel L, where a rapid combination takes place between the greater portion of
the oxygen and sulphurious acid, the sulphuric acid thus formed falls to the bottom of
the cylinder, and the uncondensed gases are forced upwards through the cup and ball
agitators marked K K' where a further portion of sulphuric acid is formed, the
remainder of the uncondensed gases, pass from No. 1 to No. 2 cylinder by the pipe N,
a jet of additional steam is blown in at the point g, and a similar reaction takes place
in No. 2 as described for No. 1, The uncondensed gases from No. 2 pass by the
pipe U¹ into No. 3 cylinder, and a jet of steam is blown in at the point which
forces the gases down upon the surface of the sulphuric acid contained in the
basin L by this means the last vestage of sulphurous acid is converted into sulphuric
acid in No. 3 cylinder. The nitrogen and nitrous gases pass from No. 3 by the pipes
N', N, into the bottom of the cylinder O, which is kept full of a solution of soda,
The gases along with an additional blast of air are forced up through the liquor
and ball agitator's K", and oscape by the valve V, The nitrous gases unite with
the oxygen of the air as they pass up through the liquor and form nitric acid which
unites with the soda, and forms nitrate of soda, The liquor in the vessel O overflous
into the evaporating pan W, by the pipe U, and is there crystalized and made
fit to be used over again in the nitre retort, a constant stream of liquor is kept
running into the vessel O, from the cistern T, by the pipe X, and overflows by the
pipe U, as soon as it is saturated with the nitric acid. After the charge in the
retort A is burnt out, the pressure is taken off the cylinders by lifting the valve V
on the vessel O, and emptying the cylinder O, by opening the valve Yin. The acid
in the cylinders No. 1, 2 and 3, is then denitrated by blowing superheated steam from
a high pressure boiler up through the acid by the pipes Z, Z, the acid is then drawn
off by the valves Y, Y, Y", into carboys. When the air pumps are worked slowly
one combining cylinder is sufficient to convert the whole of the sulphurous acid into
sulphuric acid; a slow motion causes the gases to pass in thin filims through the
agitators between the cups and balls, and the friction against the wet surfaces of
the cups and balls under pressure, causes the whole of the sulphurous acid to
combine with the oxygen of the air in the cylinder, before the gases can pass out
of the cylinder. When the air pumps are worked rapidly it is necessary to have two
or more cylinders because the balls are then forced out of the cups into the bells
and leave a wide opening for the gases to pass through in globules instead of thin
films. The rapid rising into the bells and falling of the balls into the cups causes
an agitation throughout the whole body of gases, and makes the molecules impinge
against one another, which aciton facilitates rapid combination. The strength of
the acid can be regulated by the quantity of steam admitted. The higher the
pressure at which the gases are forced into the cylinders the quicker does the coin-
bination take place; and a smaller quantity of nitric acid is required. A pressure
of an half an atmosphere gives good results. In order to save unnecessary space
and waste of gases in the combining cylinders, I proportion the three air pumps, so
as to deliver the exact proportion of atmospheric air required to form the requisite
chemical combination I make the air pump for feeding the pyrites retort A, three
times the capacity of the pump for feeding the mixer M, through the pipe P, and six
times the capacity of the pump for supplying air to the soda vessel O. In working;
one third of the oxygen of the air that enters the pyrites retort combines with the
iron of the pyrites, and, two thirds of the oxygen combines with the sulphur, and
forms sulphurous acid. The second pump, that which supplies air to the mixer,
supplies the third equivalent of oxygen to combine with the sulphurous acid to form
sulphuric acid, along with the steam admitted into M. The third air pump supples
sufficient air to furnish oxygen to convert the lower oxides of nitrogen into nitric
acid in the cylinder O.

page_text: Having now particularly described 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 manufacture of sulphuric acid by burning sulphur, or any combustible
sulphurets in air tight retorts by blowing atmospheric air under high pressure into the
said retorts, kept at a temperature sufficient to cause combustion, and then to mix the
resulting gases with nitrous gases, air, and steam, in a vessel called a mixer, and then
forcing the mixed gases under high pressure into a combining cylinder or cylinders,
constructed and operated substantially as described.
2nd. I claim the forcing of the residual uncondensed gases from the combining
cylinders into and through ammoniacal liquor, or a solution of soda, along with
atmospheric air, to form nitrate of ammonia or nitrate of soda as may be required.
3rd. I claim the use of the cup and ball agitators as described, and shewn in the
drawings.