IMPROVEMENTS IN SMELTING IRON AND OTHER ORES
Year: 1873

page_text: LETTERS PATENT to George William Hart, of Upper Norwood, in the
County of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN
SMELTING IRON AND OTHER ORES."
Sealed the 12th June 1874, and dated the 18th December 1873.
PROVISIONAL SPECIFICATION left by the said George William Hart
at the Office of the Commissioners of Patents, with his Petition,
on the 18th December 1873.
I, GEORGE WILLIAM HART, of Upper Norwood, in the County of
Surrey, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SMELTING IRON AND OTHER ORES," to be as follows: _
This Invention relates to improvements in smelting iron and other
ores, and is as follows:-I effect the smelting of iron and other ores by
the use of carbonic oxide gas introduced by any suitable means into the
furnace or cupola charged with the ore and fluxing materials at a
sufficiently high temperature to effect the reduction of the ore and
fusion of the fluxing materials.

page_text: The ore before being finally fused by the heated carbonic oxide gas
may have its temperature raised by passing through or over it the hot
waste gases of the furnace in which it is to be afterwards fused, or of
another furnace; and this may be accomplished either within the furnace
itself or in a separate chamber.
The ore may also be reduced to a state of spongy metal by the
chemical action of carbonic oxide gas passed through it before being
finally fused.
.
The heating of the carbonic oxide gas may be conveniently accom-
plished by the use of Siemen's regenerative stoves, which process is well
known and understood; or other known and suitable method of heating
gases may be employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said George William Hart in the Great Seal Patent
Office on the 18th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WILLIAM HART, of Upper Norwood, in the County of Surrey, Engineer,.
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-three,
in the thirty-seventh year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said George William Hart,
Her special license that I, the said George William Hart, my executors,
administrators, and assigns, or such others as I, the said George William
Hart, 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
"IMPROVEMENTS IN SMELTING IRON AND OTHER ORES," upon the condition
(amongst others) that I, the said George William Hart, my executors or
administrators, by an instrument in writing under my, or their, or one

page_text: heat thus evolved is utilised in raising the heat of or fusing the ore in
the vicinity of the point of combustion, and thus rendering it in a better
condition to be acted upon and reduced by the carbonic oxide still
admitted at the hearth.
The ore before being fused by the heated carbonic oxide gas admitted
at the base of the furnace may have its temperature raised by passing
. through or over it the hot waste gases of the furnace in which it is to
be afterwards fused, or of another furnace, and this may be accomplished
either in the furnace itself or in a separate chamber.
The ore may also when required be reduced to spongy metal by the
chemical action of carbonic oxide gas passed through it before fusion-in
the furnace A.
The carbonic oxide gas required for the purposes of my Invention
may be manufactured by any known and suitable means, and the
heating thereof, or of the air required may be conveniently effected by
the well-known process of Siemen's regenerative stoves, or other known
and suitable method of heating gases may be employed.
Suitable apparatus for carrying out my Invention is illustrated in the
accompanying Drawings in which Figure 1 is a sectional elevation at
the line a, b, Figure 2, which latter is a sectional plan at the line c, d,
Figure 1; Figure 3 is a sectional elevation at the line e, f, Figure 1,
looking in the direction of the arrow e¹; Figure 4 a sectional plan at the
line g, h, Figure 1; Figure 5 a part sectional elevation at the line i, j,
Figure 1, looking in the direction of the arrow ; and Figure 6 a part
sectional plan at the line k, l, Figure 5. The same letter of reference
indicates like parts of the apparatus in all the several Figures.
A is the furnace which is charged with the ore and fluxing materials;
B, are the tuyers for the introduction of the carbonic oxide gas;
C, tuyer for the introduction of the atmospheric air; D, D¹, are
chambers in which ore and fluxing materials are placed, so that the hot
gases of combustion from the furnace A may be drawn or forced
therethrough. By this means such ore and fluxing materials are raised
to a great heat, and are thus rendered in a better condition for when
they are afterwards let down into the furnace A, which latter operation
, is accomplished by drawing out the dampers d, d¹.

page_text: Communication between the furnace A and the chambers D, D¹, for
the passage of the gases of combustion is opened or closed as required
by means of the dampers d², d³, one of which (d³) is shewn open on the
Drawings and the other closed (see Figures 2, 3, and 5). The bottoms
of the chambers D, D¹, are inclined downwards towards the furnace A
and are perforated with slots d'as shewn in the Drawings (see Figures 1
and 2), and underneath passages E, E¹, are formed by inclined planes,
constructed as shewn, sloping in the direction of the perforated bottoms
of the chambers D, D¹, and at a short distance from the same. The
object of these passages E, E¹, being so formed is two-fold, viz., to
allow the gases of combustion to pass away from the bottoms of the
chambers D, D, after having passed therethrough, and secondly to
provide against the possible contingency of any of the ore contained in
the chambers D, D¹, being fused by the heat of the waste gases of com-
bustion, and so passing through the perforations in the bottom plates.
Should such event happen the fused ore would be arrested by the inclined
surfaces underneath, and so be conveyed down to the dampers d, d¹, and
when the same are opened would pass with the ore and fluxing materials
into the furnace A. The passages E, E¹, which also form the flues for
the
gases of combustion extend downwards and communicate respectively
with the under sides of two chambers or furnaces F, F¹, and may be shut
when required by dampers e, e².
The furnaces F, F', (which I term my regenerative furnaces) are filled
with coke, charcoal, or other carbonaceous substance. The highly
heated gases of combustion entering these chambers at the bottom by
the flues E, E¹, ignite the coke when so much of such gases as is
carbonic acid, dissolves an additional portion of carbon and is thus split
up into two volumes of carbonic oxide gas which may then be used as
fuel for the furnace A. The gases thus passed through my regenerative
furnaces F, F¹, issue from the tops of same through passages G, G³,
(see Figures 3 and 4) into the upper ends of two "Siemen's re-
generative stoves" H, H³, where they leave their heat behind them
and thence are led away by pipes ¹ (see Figures 1, 2, and 4), to be
stored for future use. The passages G, G³, may be closed when required
by dampers 9, 9³. The principle and method of construction of the
"Siemen's regenerative stoves" is well known and understood.
It will be observed that to one furnace A the remainder of the
apparatus is in duplicate. The object of this arrangement is to work

page_text: the two sides alternately as follows:-The damper d² being closed the
gases of combustion from the furnace A are excluded from the chamber D,
and pass into and through the chamber D³, and thence through the
chambers F¹ and H', finally leaving the latter as carbonic oxide gas (as
already explained) and gradually raising it to a great heat. When this
process has gone on long enough the damper d² which has hitherto
remained closed is opened and d³ which has been open is closed. The
gases of combustion are then caused to pass through the other set of
chambers D, F, and H, and at the same time the carbonic oxide fuel
is passed into the blast furnace by way of the pipes h² and H³ (see
Figures 1, 3, and 6), through the Siemen's regenerative stove H¹, which
has been already heated, and thus the blast is heated by the otherwise
waste heat left behind in the Siemen's regenerative stove by the gases_
of combustion. When these gases are again turned through the first
series of chambers the carbonic oxide gas is then introduced to the
furnace A through the second Siemen's stove, and so the process is
carried on alternately. The pipes ¹, h³, and h³, are of course provided
with suitable valves so that they may be opened or closed as required.
When it is desired to reduce the ore to spongy metal by the
chemical action of carbonic oxide gas passed through it before it is
introduced into the furnace A for fusion, the object is accomplished as
follows: It will be observed that when the carbonic oxide gas is being
passed through one of the Siemen's stoves into the furnace A, that one
of the chambers D, D¹, which is directly above is idle, as the gases of
combustion are passing out through the other. For instance, whilst the
carbonic oxide gas is being introduced to the furnace A through the
Siemen's stove H, the chamber D above is idle, the gases of combustion
from the furnace A passing away through the chamber D¹. If now the
damper J above the stove H (see Figures 1 and 2) be drawn out a few
inclies (more or less)' a portion of the carbonic oxide gas will pass out
of the chamber H into the passage E, and being prevented by the
dampers è and g (which are closed) from passing downwards and
through the chamber F, it ascends through the perforated bottom of the
chamber D, through the materials contained therein, and passes thence
through the perforations d³ in the division wall into the chamber D¹,
whence it issues with the gases of combustion from the furnace A. Thus
by opening the damper J, more or less, or closing it altogether, the
quantity of carbonic oxide gas passed through the chamber D and its

page_text: contents may be regulated or stopped at pleasure. A similar process is of
course adopted when the gas is required to pass through the chamber D¹.
In witness whereof, I, the said George William Hart, have hereunto
set my hand and seal, this Eighteenth day of June, in the
year of our Lord One thousand eight hundred and seventy-
four.
GEO. W. HART. (L.S.)
Witness,
J. O. M. W. GRAY, C.E.,
Offices for Patenting & Introducing Inventions,
16, Southampton Buildings,
W.C.