IMPROVEMENTS IN SMELTING IRON ORES, AND IN APPARATUS EMPLOYED IN CONNECTION THEREWITH
Year: 1871

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George
Street, Westminster, in the County of Middlesex, for the Invention
of "IMPROVEMENTS IN SMELTING IRON ORES, AND IN APPARATUS EMPLOYED
IN CONNECTION THEREWITH."
Sealed the 5th January 1872, and dated the 26th July 1871.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition,
on the 26th July 1871.
I, CHARLES WILLIAM SIEMENS, of No. 3, Great George Street, West-
5 minster, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN SMELTING IRON ORES, AND IN
APPARATUS EMPLOYED IN CONNECTION THEREWITH," to be as follows:-
In smelting iron ores in blast furnaces the combustible gases resulting
from the operation are either allowed to escape uselessly at the top of
the furnace, or are collected there and conducted below steam boilers or
heating apparatus, where they are made to yield heat in combustion.

page_text: The ironstone and fluxing materials charged at the top of the blast
furnaces have generally been calcined beforehand in order to deprive
them of their gaseous constituents, and thus diminish the amount of
heat necessary to be imparted to them in the blast furnace.
My present Invention has for its object to effect the calcination of the
orc and other materials entering the furnace within the upper portion of
the furnace itself by the combustion of the whole or of only a portion
of the gases which would otherwise escape or be withdrawn from the
furnace. For this purpose I fix over the centre of the blast furnace and
within its tunnel head a vertical cylinder of cast iron or other metal,
from which a pipe or neck descends downward into the charge of the
furnace. An inner pipe of wrought metal or steel descends through this
neck still deeper into the charge, which inner pipe is open at top and
bottom, but is suspended by means of a rod passing through the top of
the cylinder so as to admit of being raised or lowered. The cast-iron
cylinder or chamber in the tunnel head is connected through pipes with
a blast apparatus, by preference with a steam blast apparatus such as I
have described in the Specification to my Patent, No. 3255 of 1870, so
that a flow of compressed air is directed through the chamber and
through the vertical neck and pipe into the charge, where it meets
with an ascending current of the combustible furnace gases, the com-
bustion of which produces the heat necessary for calcining the ore and
limestone, and also produces this further advantage that the calcined
materials reach the ore reducing zone of the blast furnace in a highly
heated condition, whereby the work of reduction and of smelting is
greatly expedited, and a considerable saving of coke in the blast furnace
is effected. Instead of discharging the whole of the forced air from the
bottom of the descending pipe a portion may be made to pass in amongst
the charge at the mouth of the descending neck, or at any other inter-
mediate point. Or a portion of the air may be directed in amongst
the charge through blast orifices in the outer wall of the blast furnace
near its upper extremity. In giving a considerable amount of heating
surface to the blast chamber in the tunnel head the air will become
heated to a considerable degree before descending in amongst the charge.
The vapour of water mixed with the air proceeding from the steam
blower exercises a favourable chemical influence upon the ore in process
of calcination in forming volatile compounds with the phosphorus or
sulphur which they may contain.

page_text: In applying this calcining blast to blast furnaces hard coke should be
employed, which will not be consumed to any great extent in the pre-
sence of the more combustible furnace gases. The calcining heat must
also be regulated so as not to exceed the melting point of the iron ore,
which may be easily accomplished by means of a regulating valve. The
combustion of a portion of the furnace gases will generally suffice to
effect the calcination of the raw materials, and the superfluous gases
may be utilized by being withdrawn from the blast furnace by means of
a collecting gallery below the point of combustion by the blast.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles William Siemens in the Great Seal Patent
Office on the 25th January 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of No. 3, Great George Street, Westminster, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of July, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles William Siemens, Her special
licence that I, the said Charles William Siemens, my executors, dmi-
nistrators, and assigns, or such others as I, the said Charles William
Siemens, my executors, administrators, and 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 Channel Islands, and Isle of Man, an Invention for
IN APPARATUS EMPLOYED. IN.
IMPROVEMENTS IN SMELTING IRON ORES, AND
CONNECTION THERewith,” upon the condition (amongst others) that .I,, the
said Charles William Siemens, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
"

page_text: 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 Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say :—
In smelting iron ores in blast furnaces the combustible gases resulting
from the operation are either allowed to escape uselessly at the top of
the furnace, or are collected there and conducted below steam boilers or
heating apparatus, where they are made to yield heat in combustion.
The ironstone and fluxing materials charged at the top of the blast
furnaces have generally been calcined beforehand in order to deprive :
them of their gaseous constituents, and thus diminish the amount of
heat necessary to be imparted to them in the blast furnace.
My present Invention has for its object to effect the calcination and
heating of the ore and other materials entering the furnace within the
upper portion of the furnace itself by the combustion of the whole or of 2
only a portion of the gases which would otherwise escape or be with-
drawn from the furnace. For this purpose I fix over the centre of the
blast furnace and within the tunnel head a vertical cylinder of cast iron
or wrought iron or steel, from which an adjustable pipe or cone descends
downward into the charge of the furnace. The cast-iron cylinder or 2
chamber in the tunnel head is connected through pipes with a blast
apparatus, by preference with a steam blast apparatus such as I have
described in the Specification to my Patent, No. 3255, of 1870, so that a
flow of compressed air is directed through the chamber and through the
vertical pipe or cone into the charge, where it meets with an ascending 3
current of the combustible furnace gases, the combustion of which pro-
duces the heat necessary for heating or calcining the ore and limestone,
and also produces this further advantage that these materials reach the
ore reducing zone of the blast furnace in a highly heated condition,
whereby the work of reduction and of smelting is greatly expedited, and 3
a considerable saving of coke in the blast furnace is effected. Instead of
discharging the whole of the forced air from the bottom of the descend-

page_text: ing pipe a portion may be made to pass in amongst the charge at any
intermediate point through orifices of restricted area. Or a portion of
the air may be directed in amongst the charge through blast orifices in
the outer wall of the blast furnace near its upper extremity. In giving
a considerable amount of heating surface to the blast chamber in the
tunnel head the air will become heated to a considerable degree before
descending in amongst the charge: The vapour of water mixed with
the air proceeding from the steam blower exercises a favourable chemical
influence upon the ore in process of calcination in forming volatile
compounds with the phosphorus or sulphur which they may contain.
In applying this heating or calcining blast to blast furnaces hard coke
should be employed, which will not be consumed to any great extent in
the presence of the more combustible furnace gases. The heat must
also be regulated so as not to exceed the melting point of the iron ore,
which may be easily accomplished by means of a regulating valve. The
combustion of a portion of the furnace gases will generally suffice to
effect the calcination of the raw materials, and the superfluous gases
may be utilized by being withdrawn from the blast furnace by means
of a collecting gallery below the point of combustion effected by the
blast.
On the accompanying Sheet of Drawings are shewn the arrangements
which I prefer to employ in carrying my before described Invention into
practice.
Figures 1 and 2 shew respectively a vertical section and a sectional
plan of the upper part of a blast furnace with my Invention applied
thereto. Centrally in the tunnel head A is fixed a closed cylinder B,
supported by bearers C, C, on the top of the tunnel head, and in this
cylinder is a wrought iron or steel pipe D, which is extended downwards
into the charge through a neck B' on the cylinder. This pipe is open
at its upper and lower ends, and is supported at its upper end by a
transverse rod E fixed in the cylinder B. Or if it be required to provide
for a vertical adjustment of the pipe D this may be suspended from a
rod passing through the top of the cylinder B, and provided with any
suitable contrivance for raising and lowering the same. A pipe F con-
ducts the air or blast from any suitable blowing apparatus into the
cylinder B, whence it passes down, through the pipe D, and on issuing
from the lower end thereof it is made to enter into combustion with a

page_text: portion of the blast furnace gases rising up through the furnace. At the
same time other jets. of air issue into the furnace from nozzles H¹ on
the circular pipe H, which communicates with the pipe F by means of
the branch F, and these jets of air also enter into combustion with the
blast furnace gases. By these means a considerable heat is generated in
the top of the blast furnace, whereby the calcination of the ore and
limestone is effected as before described. The gaseous products of this
combustion escape through the top of the tunnel head, while the portion
of the blast furnace gases not required for maintaining such combustion
escapes through the openings I into the circular passage I¹ to be con-
ducted away and utilized for other purposes, which arrangement is well
known, and forms no part of my present Invention. As the lower end
of the pipe D may get burnt away in course of time it can be removed
and replaced by a new pipe when necessary on taking off the cover B² of
the cylinder B.
Figures 3 and 4 shew respectively a vertical section and sectional
plan of the upper part of the blast furnace with a somewhat modified
arrangement of the before described apparatus. In this arrangement
the internal pipe D is dispensed with, as are also, though not necessarily,
the air nozzles round the sides of the furnace. The air blast is made
to pass from the pipe F into the top of closed chamber B, which is
enlarged in diameter towards the lower end, and is there provided with
a number of lateral openings 6 in several tiers, through which the air
or blast issues into the furnace, and there enters into combustion with
the blast furnace gases, as before described. The chamber B is suspended
by means of loops K. from the transverse bearer L. This conc serves
also for the better distribution of the charge in the furnace.
Having thus described the nature of my said Invention, and in what
manner the same is to be performed, what I claim is,—
First. Calcining and heating the ore and fluxing materials in the
upper part of a blast furnace by there introducing a blast of air, so as
to enter into combustion with the blast furnace gases, substantially as
herein-before described.
Second. The use of steam in combination with such aforesaid air blast
introduced into the upper part of blast furnaces for combining with
the phosphorus or sulphur in the ore, substantially as herein-before
described.

page_text: Third. Constructing apparatus for calcining and heating ores and
fluxing materials in the upper part of the blast furnaces arranged and
operating substantially as herein-before described.
.
In witness whereof, I, the said Charles William Siemens, have
hereunto set my hand and scal, this Twenty-fourth day of
January, in the year of our Lord One thousand cight hundred
and seventy-two.
C. WILLIAM SIEMENS. (L.S.)
Witness,
CHA. D. ABEL,
20, Southampton Buildings.