AN IMPROVED PROCESS FOR EXTRACTING SULPHUROUS ACID FROM THE FUMES OF FURNACES, OVENS AND SUCH
Year: 1883

page_text: LETTERS PATENT to Edwin Ambrose Brydges of the firm of Brydges & Co
Engineers and Patent Solicitors, of 107 Königgrätzer Str in the City of Berlin
and German Empire for an Invention of AN IMPROVED PROCESS FOR EXTRACTING
SULPHUROUS ACID FROM THE FUMES OF FURNACES, OVENS AND SUCH commu-
nicated to him by E. Hänisch and D M. Schröder of Rosdzin in the German
Empire aforesaid
PROVISIONAL SPECIFICATION left by the said Edwin Aubrose Brydges at
the Office of the Commissioners of Patents on the 26th May 1883.
EDWIN AMBROSE BRYDGES of the firm of Brydges & C° Engineers and Patent
Solicitors of 107 Koeniggraetzer Str in the City of Berlin and German Empire.
AN IMPROVED PROCESS FOR EXTRACTING SULPHUROUS ACID FROM THE FUMES OF
FURNACES OVENS AND SUCH a communication to me by E Hänisch and
Dr M. Schröder of Rosdzin in the German Empire
This invention relates to an improved process for extracting sulphurous acid
from the fumes of furnaces by means of water, and the utilizing of the absorbed.
sulphurous acid with small consumption of firing material. The object of this
said process is to produce gases which are free from detrimental impurities and
possess a higher degree of (S. O*) sulphurous acid and (0) oxygen than even those
gases obtained by the combustion of sulphur.
These said gases are produced from the gases containing little sulphurous acid
resulting from metallurgic process and which said gases are mixed with the
products of the combustion of coal or other fuel employed in such said metallurgic
process.
The object of this said invention is further to produce pure gas from such gases
which can be employed for the direct manufacture of sulphuric acid.
This process is carried out by first depriving the cooled furnace fumes or the gas
employed of their or its sulphurous acid by means of cold water, which said method

page_text: will give perfect results when a sufficient quantity of finely divided water is
employed.
The concentration of the solution so obtained depends on the sulphurous acid SO'
contained in the said furnace fumes.
With gases containing 1 per cent sulphurous acid (SO2) one cubic meter water
absorbs three to four Kilos sulphurous acid S. 0%, with gases containing two and
a half per cent sulphurous acid, eight to ten Kilos are absorbed and with richer
gases more in proportion
The acid water so obtained is again deoxydized by being heated to 100° Centi-
grade and afterwards converted into spray and at the same time admitting hot
air to the same.
Gases will hereby be formed which consist of about 20 vol: per cent sulphurous
acid S O2 and 80 vol: per cent air (with 16.8 vol: per cent oxygen O) so that
owing to their high concentration they would possess the required surplus of
above 6 vol per cent oxygen (O) for the production of sulphuric acid.
The heating of the cold water to 100° Centigrade would however, if effected
direct by fuel, require a great quantity of the latter, so that the process would not
be economical.
As on the deoxydation of the boiling water and especially when hot air is
employed only a small portion of the heat would be lost with the escaping gases,
the greater portion of the said heat would remain in the deoxydized hot water.
This quantity of heat is again to be applied or transferred to the following acid
and cold water, as both kinds of water are separated by thin metal plates and flow
in opossite directions to each other for some time.
By continuous operations the cold water will gradually get warm, while the
temperature of the hot water will be decreased in the same proportion.
A certain amount of heat will however, be lost, as during the circulation of the
two kinds of water in opposite directions, a certain cooling difference must exist
between their temperatures, which difference depends on the thickness of the
plates and the length of contact.
With plates of 5 Centimeter thickness and a flow of 10 to 12 minutes duration,
the difference of temperature between the two kinds of water at all parts of the
warming apparatus will be about 10° Centigrade, so that for example the temperature
of the cold water will rise from 20° to 90°, whereas, the temperature of the hot
deoxydized water will fall from 100° to 30°.
The heat of the furnace fumes is utilized to counterbalance this loss of heat.
If in certain cases these should prove insufficient a certain quantity of fuel would
have to be expended.
After the warmth of the furnace fumes or gases have been utilized in the first
apparatus, the same enter the lower part of the deoxydizing tower by means of a
suitable pipe flow in opposite direction to the descending water and are sucked
down through a suitable pipe by means of a ventilator.
The tower contains either lattice work, wicker work, roses or other equivalent,
in order to attain a fine subdivision of the water entering the tower from above and
streaming down.
The acidulous water passes off from the tower into a closed reservoir located
somewhat lower than the said tower.
The said tower and also the reservoir are placed on suitable raised supports so
that the water is under sufficient pressure to ensure its passage through the next
apparatus.
From the reservoir the water is led through a pipe which has a fall of about
5 meters into the lowest layer of the fore-warming apparatus which consists of
15 square leadenplates of 3 millimeters thickness, and of 49 square meters
surface, which are located above each other at a distance of about 10 centimeters,
so as to form 14 square spaces of 49 square meters surface and 10 Centimeters
height. The water passes the lowest and first layer from left to right and after

page_text: passing the side connection which extends the whole length of the surface, enters
the third layer, passes here from right to left and so on into the 5th, 7th to the
13th layer.
The 2, 4, 6 to 14th layer serve to allow the hot and already deoxydized water to
flow downwards.
The currents of the latter cross the currents of the ascending acidulous water in
a right angle so that the descending deoxydized water crosses at the front and rear
side of the apparatus.
In order to prevent the apparatus from being bent through the weight resting
upon the same leaden supports are so arranged between the plates of the different
layers that they are always in the direction of the current of the water as the
thin leaden partitions permit a ready transmission of heat, so that the rising cold
water is gradually warmed, while the hot descending water is cooled in the same
proportion.
The height of the different layers has for greater clearness been stated to be 10
millimeters, but to obtain a greater effect in the practical, working of the same a
height of 5 millimeters should only be allowed.
The water warmed in the forewarming apparatus escapes and passes through a
suitable pipe into the heating apparatus in which the warmth escaping with the
furnace fumes is utilized for further heating the said water, whereby a partial
cooling of the fumes also takes place.
The heating apparatus consists of a number of closed, leaden vessels placed one
above the other at a distance of about 0, 2 meter, which said leaden vessels are of
moderate height but considerable length, through which the water is to circulate
alternately from the bottom upwards. The water enters the lowest lead pan,
therefore in the opposite direction from the furnace fumes and passing in front
through two side pipes, enters the next higher vessel, and circulates here from the
front to the rear etc, until it escapes through the outlet pipe.
The leaden vessels are placed on iron plates which are on one side let into the
brickwork and also supported by columns or other suitable supports.
The furnace fumes or gases pass through the flat canals running between the
vessels and warm the water in the vessels above and below.
The lead plates are protected from doubling up by leaden supports which are
placed in the direction of the circulating water, but do not reach up to the front
walls so as to allow the water to enter freely into the separate compartments. The
water must be kept in this apparatus until it has attained a temperature of
100° Centigrade. To receive any gases that may be formed, perpendicular pipes
are to be connected to the crossing points, which lead into the main pipe. The
current in this apparatus is also caused by the pressure of the water in the higher
situated Reservoir.
In the centre of the tower is
which carries in distances of
sheet iron disks lined with
These said discs are arranged
The water after being heated to 100° Centigrade now passes through a suitable
pipe into the deoxydizing tower which is a round tower measuring 3 meters in
height and 3 meters in diameter, the bottom of which is a trifle higher than the
upper part of the forewarming apparatus so that the deoxydized hot water can run
off through a suitable pipe into the said apparatus.
arranged a vertical lead covered iron rotary shaft
0,25 meter apart a number of horizontally arranged
lead, which said dises measure 2 meters in diameter.
to run between the same number of rings of the same material, which are attached
to the inner walls of the tower and are provided with apertures of 1 meter in
diameter. A tube leads into the lower part of the tower, which said tube or pipe
serves for the supply of hot air.
The tower also serves as Reservoir for the deoxydized water.
The hot acidulous water falling onto the upper disc on the rotary shaft is thrown
off by centrifugal force and falls upon the first ring and from there onto the second
disc and so on, until it reaches the reservoir below,

page_text: In sucking down the gases a vacuum is produced in the upper part of the tower
whereby air is drawn in from below so as to free the finely divided hot water from
sulphurous acid.
The water feed and air admittance are regulated by means of suitable cocks or
valves.
In order to avoid loss of warmth the apparatus and the tubes or pipes are covered
with nonconducting material.
The gases now escaping are led into the main pipe and from this said pipe into
the lead compartments or otherwise in order that the same may be applied to
various technical purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edwin Ambrose Brydges in the Great Seal Patent Office on the
26th November 1883.
EDWIN AMBROSE BRYDGES of the firm of Brydges & C° Engineers and Patent
Solicitors of 107 Koeniggraetzer Str in the City of Berlin and German Empire
AN IMPROVED PROCSS [sic] FOR EXTRACTING SULPHUROUS ACID FROM THE FUMES
FURNACES, OVENS AND SUCH a communication to me by E. Hänisch and
D M. Schroeder of Rosdzin in the German Empire
This Invention relates to an improved process for extracting sulphurous acid
from the fumes of furnaces by means of water, and the utilizing of the absorbed
sulphurous acid with small consumption of firing material. The object of this said
process is to produce gases which are free from detrimental impurities and possess
a higher degree of (SO) sulphurous acid and (0) oxygen than even those gases
obtained by the combustion of sulphur.
These said gases are produced from the gases containing little sulphurous acid
resulting from metallurgic process and which said gases are mixed with the
products of the combustion of coal or other fuel employed in such said metallurgic
process. The object of this said invention is further, to produce pure gas from
such gases which can be employed for the direct manufacture of sulphuric acid.
This process is carried out by first depriving the cooled furnace fumes or the gas
employed of their or its sulphurous acid by means of cold water, which said
method will give perfect results when a sufficient quantity of finely divided water
is employed.
The concentration of the solution so obtained depends on the sulphurous acid
SO contained in the said furnace fumes.
With gases containing 1 per cent sulphurous acid (SO) one cubicmeter water
absorbes three to four Kilos sulphurous acid SO2, with gases containing two and a
half per cent sulphurous acid, eight to ten Kilos are absorbed and with richer gases
more in proportion.
The acid water so obtained is again deoxydized by being heated to 100°
Centigrade and afterwards converted into spray and at the same time admitting
hot air to the same.
Gases will hereby be formed which consist of about 20 vol: per cent sulphurous
acid S. O and 80 vol: per cent air (with 16.8 vol: per cent oxygen O) so that
owing to their high concentration they would possess the required surplus of
above 6 vol: per cent oxygen (O) for the production of sulphuric acid.
The heating of the cold water to 100° Centigrade would however, if effected
direct by fuel, require a great quantity of the latter, so that the process would not
be economical. As on the deoxydation of the boiling water and especially when
hot air is employed, only a small portion of the beat would be lost with the
escaping gases, the greater portion of the said heat would remain in the deoxydised
hot water.
This quantity of heat is again to be applied or transferred to the following acid
and cold water, as both kinds of water are separated by thin metal plates and flow
in opposite directions to each other for some time.
By continuous operations the cold water will gradually get warm, while the
temperature of the hot water will be decreased in the same proportion.
A certain amount of heat will however, be lost, as during the circulation of the
two kinds of water in opposite directions a certain cooling difference must exist
between their temperatures, which difference depends on the thickness of the plates
and the length of contact.

page_text: With plates of 5 Centimeter thickness and a flow of 10 to 12 minutes duration,
the difference of temperature between the two kinds of water at all parts of the
warming apparatus will be about 10° Centigrade so that for example the tempe-
rature of the cold water will rise from 20° to 90° whereas the temperature of the
hot deoxydized water will fall from 100° to 30°.
If
The heat of the furnace fumes is utilized to counterbalance this loss of heat.
in certain cases these should prove insufficient, a certain quantity of fuel would
have to be expended.
As the separate dimensions of the apparatus do not depend solely on the quantity
of furnace fumes to be deoxydized, but also on the quantity of acid contained in
the same, the general principle of the process only is shown in the accompanying
drawings-The drawing consists of the following separate parts:-1 The furnace
fume or gas deoxydizing tower A (Fig 1) in plan or top view and Fig: 2 in
vertical section-2nd The Reservoir C for the reception of the acid water coming
from the tower. Fig: 1 and 2.-3ª The Preliminary warmer D Fig 1–Fig 3
section on the line K. L.-Fig: 4 section on the line H. F.--4th The heating
apparatus B-Fig 1 and 2, Fig 5 section on the line M. N-Fig: 6 section on the
line O. P. 5 The tower in which the gas is produced C. Fig. 1 and 4.
After the warmth of the furnace fumes or gases have been utilized in the first
apparatus B the same enter the lower part of the deoxydizing tower A by means of
a suitable pipe a, flow in opposite direction to the descending water and are sucked
down through a suitable pipe b by means of a ventilator.
The tower contains either lattice work, wicker work, roses or other equivalent
in order to attain a fine subdivision of the water entering the tower from above
and streaming down
The acidulous water passes off from the tower into a closed reservoir C located
somewhat lower than the said tower.
The said tower and also the reservoir are placed on suitable raised supports s0
that the water is under sufficient pressure to ensure its passage, through the next
apparatus.
From the reservoir the water is led through a pipe c which has a fall of about
5 meters into the lowest layer d of the forewarming apparatus D this according to
the drawings consists of 15 square leaden plates of 3 millimeter thickness, and of
49 square meters surface, which are located above each other at a distance of about
10 centimeters, so as to form 14 square spaces of 49 square meters surface and
10 centimeters height. The water passes the lowest and first layer from left to
right and after passing the side connection e which extends the whole length of
the surface, enters the third layer, passes here from right to left and so on into the
5th 7th to the 13th layer.
The 2nd, 4th, 6th to 14th layer serve to allow the hot and already deoxydized
water to flow downwards
The currents of the latter on the water entering at g cross the currents of the
ascending acidulous water in a right angle so that the descending deoxydized
water crosses at the front and rear side of the apparatus. In order to prevent the
apparatus from being bent through the weight resting upon the same, leaden
supports are arranged between the plates of the different layers that they are
always in the direction of the current of the water as the thin leaden partitions
permit a ready transmission of heat so that the rising cold water is gradually
warmed, while the hot descending water is cooled in the same proportion.
The height of the different layers has, for greater clearness been shown in the
accompanying drawing to be 10 millimeter, but to obtain a greater effect in the
practical working of the same, a height of 5 millimeter should only be allowed.
The water warmed in the forewarming apparatus D escapes at f and passes through
a suitable pipe i into the heating apparatus B in which the warmth escaping with
the furnace fumes is utilized for further heating the said water whereby a partial
cooling of the fumes also takes place.
The heating apparatus B consists of a number of closed leaden vessels m placed one

page_text: above the other at a distance of about 0,2 meter which said leaden vessels are of
moderate height but considerable length through which the water is to circulate
alternately from the bottom upwards. The water enters the lowest lead pan at K
therefore in the opposite direction from the furnace fumes and passing in front
through two side pipes, enters the next higher vessel and circulates here from the
front to the rear etc until it escapes through the outlet pipe l. The leaden vessels
are placed on iron plates which are on one side let into the brickwork and also
supported by columns or other suitable supports.
The furnace fumes or gases pass through the flat canals n running between the
vessels in the direction of the arrow, and warm the water in the vessels above and
below.
The lead plates are protected from doubling up by leaden supports which are
placed in the direction of the circulating water, but do not reach up to the front
walls so as to allow the water to enter freely into the separate compartments.
The water must be kept in this apparatus until it has attained a temperature of
100° Centigrade
To receive any gases that may be formed, perpendicular pipes are to be
connected to the crossing points, which lead into the main pipe q. The current in
this apparatus is also caused by the pressure of the water in the higher situated
Reservoir C.
The water after being heated to 100° Centigrade now passes through a suitable
pipe e into the deoxydizing tower E which is a round tower measuring 3 meters
in height and 3 meters in diameter, the bottom of which is a trifle higher than the
upper part of the fore warming apparatus D so that the deoxydized hot water can
run off through a suitable pipe o into the said apparatus.
In the centre of the tower is arranged a vertical lead covered iron rotary shaft
which carries in distances of 0,25 meter apart a number of horizontally arranged
sheet iron discs lined with lead, which said discs measure 2 meters in diameter―
These said discs are arranged to run between the same number of rings of the
same material, which are, attached to the inner walls of the tower and are provided
with apertures of 1 meter in diameter.
A tube p leads into the lower part of the tower, which said tube or pipe serves
for the supply of hot air.
The tower also serves as Reservoir for the deoxydized water.
The hot acidulous water falling onto the upper disc on the rotary shaft, is
thrown off by centrifugal force and falls upon the first ring and from there onto
the second disc and so on, until it reaches the reservoir below.
In sucking down the gases a vacuum is produced in the upper part of the
tower whereby air is drawn in from below so as to free the finely divided hot
water from sulphurous acid.
The water feed and air admittance are regulated by means of suitable cocks or
valves.
In order to avoid loss of warmth the apparatus and the tubes or pipes are
covered with nonconducting material.
The gases now escaping are led into the main pipe and from this said pipe into
the lead compartiments or otherwise in order that the same may be applied to
various technical purposes.
Having now described my said Invention and the manner in which the same is
to or may be carried into effect I wish it to be understood that what I claim and
desire to secure by Letters Patent is.-
1-The improved process for extracting sulphurous acid from the fumes of
furnaces, consisting in absorbing the gaseous acid by means of a fine shower of
cold water which said so acidulated water is warmed by the furnace fumes up to
about 100° Centigrade and is then finely subdivided in a special apparatus in
which said apparatus the water is deoxydized or the sulphurous acid is removed or
separated out of the said acidulated water by means of a certain quantity of
atmospheric air admitted into the apparatus for such said purpose so that a gas

page_text: mixture containing pure sulphurous acid and the necessary quantity of oxygen is
obtained which is admirably adapted for the manufacture of sulphuric acid
substantially as described and shown in the accompanying drawings.
2-The application and employment of the apparatus D consisting of a series of
flat compartments or chambers composed of leaden plates and strengthened by
leaden supports in order to transmit the warmth of the hot water freed from acid
to the cold acidulated water which said warm water and cold acidulated water pass
in such manner through the said leaden compartments or chambers that the
ascending acidulated water or water containing acid passes successively through
the chambers or compartments corresponding to the uneven numbers in alternately
opposite direction whereas the descending water freed from acid passes through
the interposed chambers so that the direction of the flow of this water is at a
right angle to the direction of the flow of the first named acidulated water
substantially as described and shown in the accompanying drawings.
3-The application and employment of the apparatus B for regenerating the
warmth of the furnace fumes (in which said apparatus the warmth of the furnace
fumes or gases is transmitted to the acidulated water) consisting of a series of
leaden chambers or compartments which are in connection with and are located
above and behind each other in the extended or widened flue or canal, are stiffened
or strengthened by means of leaden troughs and around which the furnace fumes
play or pass so that the said fumes transinit their warmth to the acidulated water
passing or flowing through the said chambers or compartments substantially as
described and shown in the accompanying drawings
4 The process of deoxydizing or removing the acid from the water containing
SO (sulphurous acid) which said water is heated to about 100° Centigrade in such
manner that the water is converted into spray or very fine rainlike condition
through which atmospheric air is passed in opposite direction so that the SO2 or
sulphurous acid is separated out of or removed from the said water substantially as
described in the foregoing specification and shown in the accompanying drawings.
5-The construction application and employment of the apparatus E for reducing
or connecting the acidulated water into spray consisting of a series of horizontal
circular dises which are carried by a suitable vertical shaft which said shaft rotates
in a circular tower to the walls of which a row of annular discs are affixed one
above the other so that the same project between the discs on the rotary shaft
in which manner the acidulated water passing onto the discs on the said rotary
shaft is ejected or forced by centrifugal force between two of the annular discs
attached to the interior walls of the circular tower and passes from thence onto
the second rotary disc whereas atmospheric air is simultaneously sucked up from
below in opposite direction, passes through the spray or fine rainlike acidulated
water and absorbs the acid out of the same substantially as described and shown
in the accompanying drawings.
In witness whereof I the said Edwin Ambrose Brydges have hereunto set my
hand and seal this thirteenth day of September in the year of our Lord One
thousand eight hundred and eighty three.
Witnesses:
E. STUTZER.
ANTHONY STEFFEN
EDWIN A BRYDGES (L.S.)