IMPROVEMENTS IN FURNACES FOR SMELTING AND MELTING ORES AND METALS
Year: 1877

page_text: LETTERS PATENT to Josiah Swain, of Oldham; in the County of Lancaster,
Engineer, for the Invention of "IMPROVEMENTS IN FURNACES FOR SMELTING
AND MELTING ORES AND METALS."
Sealed the 27th July 1877, and dated the 15th February 1877.
PROVISIONAL SPECIFICATION left by the said Josiah Swain at the Office
of the Commissioners of Patents on the 15th February 1877.
JOSIAH SWAIN, of Oldham, in the County of Lancaster, Engineer.
MENTS IN FURNACES FOR SMELTING AND MELTING ORES AND METALS."
"IMPROVE-
My Invention relates more particularly to furnaces employed in the melting of
iron or steel, or in the smelting of iron ore, and consists in the first place in forming
chambers behind or within the linings or walls of the furnace, into which chambers
air is forced. I form chambers surrounding the linings or inner shell of the furnace,
and the tuyeres or tuyere pipes and the slag box or other parts of the furnace, the said
chambers being formed so that air forced into one chamber may be conveyed into
another or into other chambers successively, the air tending to preserve the linings
or walls of the furnace and becoming heated. The air so heated may be conveyed
to the tuyeres to be employed as a hot blast.
In some cases I may provide means for separately supplying each chamber or
certain of the chambers with air in order that cool air may be forced into more than
one chamber.
In some cases I may employ perforated bricks as a lining for upper parts of the
furnace, or I may dispense with a brick lining and depend upon the supply of air to
prevent over heating of the metal shell or lining.
I prefer to form the passages for the flow of air from one chamber to the other
close to the inner shell or lining, so that the flowing air may be caused to impinge
on the said shell or lining. In case the furnace be provided with a metal receiver I
form similar air chambers in the walls and crown of the said receiver.

page_text: According to a second part of my Invention I provide the mouth of the furnace
with a cage to contain the charge of metal or ore, in order that the said charge may
be roasted or heated to some extent before entering the furnace.
In one arrangement the said cage consists of an inner and outer part, both per-
forated or formed of bars or with slots. Between the two parts is an annular space
to receive the said charge and also the limestone if any be used. The fuel is fed
through a central passage in the inner of the two parts which may or may not be
provided with a cover. The charge may be discharged into the furnace by lowering
or by raising one of the two parts, according to the form and arrangement of the
said parts.
A third part of my Invention consists in the employment of an oven or of ovens
in which the charge of ore or metal or masses of metal may be heated before
entering the furnace. The said oven or ovens is or are formed at the upper part of
the furnace, and a damper or valve is provided so that when the said damper or
valve is closed the flames and heated gases are deflected and caused to flow through
the oven or ovens. The said ovens may be of a similar form to reverberatory
furnaces, and may or may not be provided with dampers or valves to be closed
when the ovens are not required.
A remaining part of my Invention relates to "close top" blast furnaces, and
consists in forming the "bell" with a central opening which is surrounded by a
second hopper in which the charge of fuel is placed. The said central opening is
closed by a second bell or by a suitable form of plug or valve. The fuel being
discharged through the said central opening falls more centrally within the furnace
than is the case with the ordinary arrangement.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Josiah Swain in the Great Seal Patent Office on the 15th August
1877.
JOSIAH SWAIN, of Oldham, in the County of Lancaster, Engineer.
MENTS IN FURNACES FOR SMELTING AND MELTING ORES AND METALS."
"IMPROVE-
My Invention relates more particularly to furnaces employed in the melting of
iron or steel, or in the smelting of iron ore, and consists in the first place in forming
chambers behind or within the linings or walls of the furnace into which chambers
air is forced. I form chambers or air spaces surrounding the linings or inner shell
of the furnace and the tuyeres or tuyere pipes and the slag box or other parts of the
furnace, the said chambers being formed so that air forced into one chamber may be
conveyed into another or into other chambers successively, the air tending to
preserve the linings or walls of the furnace and becoming heated.
According to a second part of my Invention I provide the mouth of the furnace
with a cage to contain the charge of metal or ore, in order that the said charge may
be roasted or heated to some extent before entering the furnace.
A third part of my Invention consists in the formation near the upper part of the
furnace of an oven or of ovens in which the charge of ore or metal or masses of
metal may be heated before entering the furnace.
A remaining part of my Invention relates to "close top" blast furnaces, and
consists in forming the "bell" with a central opening which is surrounded by a
second hopper in which the charge or part of the charge of fuel is placed.
And in order that my Invention may be well understood, I have appended hereto
two Sheets of Drawings marked with letters of reference, to which I will now
refer.

page_text: ;
Sheet 1 of the said Drawings is illustrative of the first and second parts of my
Invention, Fig. 1, drawn to a scale of about three-eights of an inch to the foot, repre-
senting a vertical section of a cupola; and Fig. 2, an elevation of the same.
In the
said Figures a is the outer and ordinary metal shell of the cupola; within this is
fixed an inner metal shell b which surrounds the inner fire-brick lining c and
extends upwards above the said lining, which in this example does not extend so
high as in ordinary cupolas; between the two shells is an air space; in the
example the said inner shell is made of cast-iron rings resting one upon another and
formed with flanched or socket joints, which if considered advisable may be turned
when so constructed the rings may be replaced as they become burnt or worn out ;
the space between the two shells is divided into chambers by horizontal partitions d
which are cast upon the said rings or are fixed in position as preferred; each
partition does not extend entirely around the.furnace, and the openings left between
the ends of the partitions are by preference situated alternately on opposite sides of
the furnace. A pipe e conveys the air blast into the lower end of the air space,
and the air flows around the inner shell and passes upwards through the opening in
the partition at d; the air then again flows around the said shell and passes upwards
through the opening at d².
It will be seen that as the air flows upwards it is also caused to flow to and fro
around the furnace until it arrives in a highly heated state at the upper end of the
air space whence it flows into a pipe f which conveys the air to the tuyeres g.
Each tuyere is surrounded by an air space which communicates with the main air
space, and I prefer to permit of a comparatively slight escape of the cool air around
the mouth of the tuyere nozzle and into the furnace, whereby the employment of
water to keep the tuyeres cool is dispensed with.
If preferred the air may flow from one chamber to another through passages
formed in the partitions at different points in the circumference of the furnace and
close to the inner shell, so that the flowing air may be caused to impinge on the said
shell; or the partitions may be otherwise arranged so as to ensure that the flowing
air shall be brought into contact with the inner shell so as to abstract heat there-
from; the upper part of the said inner shell may also be lined with fire-bricks or
refractory material, or with perforated fire-bricks or lumps if considered to be
advisable.
If preferred the said inner lining may be made of wrought iron or steel instead of
cast iron.
In some cases I may provide means for separately supplying each chamber or
certain of the chambers with air, in order that cool air may be forced directly into
more than one chamber, or into one or more of the upper chambers. Within the
furnace is suspended a cage A in accordance with the second part of my Invention ;
the said cage consists of an inner part h and an outer part i, both perforated or
formed of bars or with slots. Between the two parts is an annular space to receive
the charge of metal or ore. The limestone may also be placed within the said cage.
Each of the two parts of the cage is suspended by means of a separate chain which
is led to a crab or purchase. When the charge has become sufficiently roasted it
may be discharged into the furnace by lowering the inner part or by raising the
outer part, or by lowering the inner part and raising the outer part at the same
time. The fuel or part of the fuel may be fed to the furnace through the central
passage in the inner cage.
The form and arrangement of this cage may be varied, and the said cage may be
used without the first part of my Invention.
The third part of my Invention is illustrated by Fig. 3, in Sheet 2. This Figure
represents the upper part of a cupola or furnace provided with two heating ovens
B, B. The said ovens are formed at the upper part of the furnace, and communicate
by their inner ends with the interior of the furnace.
Dampers or sliding shutters or doors arranged to be raised and lowered are applied
at C-at the top of the furnace, in order that the exit of the flames or heated gases at

page_text: that point may be prevented or be checked. The outer end of each oven commu-
nicates with a pipe flue or passage D which opens into the upper part of the furnace
above the doors C. The communication between each oven and the furnace may
be closed by means of a damper E whenever required. Charges of ore or metal or
large masses of metal are placed within or fed into the ovens through charging
doors F which are provided with suitable doors. The dampers E are opened and
the damper or door C closed or partly closed, whereby the flames or heated gases or
portions of them are deflected and compelled to pass through the ovens and the
pipes D, D, whereby the contents of the ovens become heated. When sufficiently
heated or at suitable intervals the charges within the ovens are pushed down into
the furnace to be melted or smelted.
To facilitate the transfer of the charges to the furnace and the flow of the heated
gases, the bottoms of the ovens slope in the example, but I do not confine myself to
the angles of slope indicated.
The two ovens are by preference charged and emptied alternately, but I do not
confine myself to the use of two ovens, nor to the number of ovens.
The lower part of the furnace in some cases may be construeted in accordance
with the first part of my Invention.
Fig. 4 illustrates the fourth part of my Invention, and represents the upper part
of a close top blast furnace. In this example a bell G is substituted for the ordinary
bell. The improved bell is in the form of a truncated cone, and to it is fixed a
cylinder K, upon the upper end of which is formed or fixed a conical hopper l.
The passage through the cylinder k is closed by means of a bell or valve m.
chain and crab or a lever and links or other means are provided for raising the said
valve. Means are also provided for raising and lowering the bell G together
with the attached cylinder and hopper; as in the case of the ordinary bells of close
top furnaces.
A
The fuel
The ore and limestone and a small portion of the coke or fuel are placed in the
lower hopper surrounding the bell G. The larger portion of the charge of coke or
fuel is placed within the upper hopper 7. The charge in the lower hopper is dis-
The fuel in
charged into the furnace by lowering the bell G in the usual manner.
the upper hopper is discharged into the furnace by raising the valve m.
.descends through the cylinder into the furnace, and forms a central column of
fuel which unites with the small portion previously discharged from the lower
hopper, and immediate combustion takes place. I consider that the employment of
this arrangement prevents "hanging" or scaffolding, and promotes uniformity in
the quality of metal produced.
Having now fully set forth and indicated the nature of my said Invention, and
methods whereby the same may be carried into effect, I would have it to be under-
stood that I claim,―
First. The air space or air chambers constructed within the outer shell and sur-
rounding the furnace, substantially as and for the purposes set forth and indicated
herein-before and in and by the accompanying Drawings.
Secondly. The spaces around the tuyeres supplied with air, substantially as and
for the purpose set forth and indicated.
Thirdly. The method of heating the air blast, substantially as set forth and
indicated.
Fourthly. The cage suspended within the throat of the furnace, substantially as
and for the purpose set forth and indicated.
Fifthly. The ovens for heating the charges before admission to the furnace, sub-
stantially as set forth and indicated.
Sixthly. The arrangement, substantially as and for the purpose set forth and
indicated herein-before with reference to Fig. 3 of the accompanying Drawings.
... And, lastly. The arrangement, substantially as and for the purpose set forth

page_text: and indicated herein-before with reference to Fig. 4 of the accompanying
Drawings.
In witness whereof, I, the said Josiah Swain, have hereunto set my hand
and seal, this Fourteenth day of August, in the year of our Lord One thou-
sand eight hundred and seventy-seven.
Signed and sealed by the
said Josiah Swain, in
the presence of
EDWARD K. DUTTON,
Agent to the Patentees,
3, Princess Street,
Manchester.
JOSIAH SWAIN. (LS.)