IMPROVEMENTS IN THE CONSTRUCTION OF ANREACTS FOR THE MANUFACTURE OF IRON AND STEEL
Year: 1870

page_text: LETTERS PATENT to Josiah Swain, of Oldham, in the County of
Lancaster, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF ANREACTS FOR THE MANUFACTURE OF IRON AND STEEL."
Sealed the 6th September 1870, and dated the 16th June 1870.
PROVISIONAL SPECIFICATION left by the said Josiah Swain at the
Office of the Commissioners of Patents, with his Petition, on the
16th June 1870.
I, JOSIAH SWAIN, of Oldham, in the County of Lancaster, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF FURNACES FOR THE MANUFACTURE OF IRON AND STEEL," to be as
follows:-
:-
My Invention relates principally to the construction of what are
called "cupola" furnaces employed in the manufacture of iron and
steel. Instead of placing the "tuyeres" by which the blast is intro-
duced at the "boshes or some distance above the sole of the furnace;
as hitherto practised, I place them just above the sole of the furnace,
and cause the latter to slope or incline towards the front where there
"

page_text: are formed perforations and a passage leading in an inclined direction
downwards into a receiver placed at a lower level than the sole of the
furnace. At the bottom of the receiver, and on the opposite side to the
inclined passage before named, is a spout which can be opened or closed
as required, and higher up in the side of the said receiver, about level
with the sole of the cupola and below the tuyères, is a slag hole for the
discharge of the slag or scoria from the surface of the molten metal.
On the other side of the receiver about opposite to the slag hole is a
flue leading to the chimney which is provided with a damper which
can be opened and closed at pleasure.
The method of working this furnace is as follows:-The cupola being
charged with pig iron and coke or other fuel in the usual manner, the
damper in the flue is closed and the spout of the receiver opened, the
fire is lighted at the bottom in the ordinary way and the blast turned
The blast (and with it the flame and heated gases) passes through
the lower part of the receiver and escapes by the spout.
on.
When the bottom of the receiver has thus been thoroughly heated,
and before the metal begins to flow, the spout is closed and the damper
in the flue leading to the chimney opened. As the metal at the bottom
of the cupola melts it runs through the perforations and down the
inclined passage into the receiver (the charge falling down gradually
in the cupola) and as the blast passes over it continually in its way to
the chimney it keeps it always in a molten state.
By the use of a furnace of this description the metal melts quicker
than in the old furnace, it is kept hotter, and is consequently better
purified, and as the blast does not pass up through the charge the coke
or fuel does not become consumed before it is required for melting the
charge, and hence a much smaller quantity of coke or fuel than heretofore
is required to melt a given amount of metal. The receiver may be
made of any size, and thus a much larger quantity of metal can be run
from one furnace at a time than under the usual process.
In some cases in place of the receiver I use an air or reverberatory
furnace into which the metal runs as it is melted, and this furnace may
be charged with large lumps of steel or with wrought-iron turnings
or borings or with other iron or steel which it may be desired to mix
or incorporate with the cast iron.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Josiah Swain in the Great Seal Patent Office on the
16th December 1870.
-
TO ALL TO WHOM THESE PRESENTS SHALL COME, I. JOSIAH
SWAIN, of Oldham, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of June, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Josiah Swain, Her special license
that I, the said Josiah Swain, my executors, administrators, and assigns,
or such others as I, the said Josiah. Swain; my executors, adminis-
trators, 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 THE CONSTRUCTION
OF FURNACES FOR THE MANUFACTURE OF IRON AND STEEL," upon the condition
(amongst others) that I, the said Josiah Swain, my executors or
administrators, by an instrument in writing, under I, 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 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 Josiah Swain, 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 and accompanying Drawings (that is to say):-
My Invention relates principally to the construction of what are called
cupola furnaces employed in the manufacture of iron and steel. Instead
of placing the "tuyères" by which the blast is introduced at the
"boshes," or some distance above the sole of the furnace, as hitherto
practised, I place them just above the sole of the furnace, or I raise the
sole of the furnace nearly up to the level of the "tuyères," and cause
the sole of the furnace to slope or incline towards the front, where there
are formed perforations or passages leading in an inclined direction

page_text: downwards into a receiver placed at a lower level than the sole of the
furnace. At the bottom of the receiver and on the opposite side to the
inclined passages before named is a spout and a tapping hole, which can
be opened or closed as required; and higher up in the side of the
receiver, about level with the sole of the cupola and below the tuyères,
is a slag hole for the discharge of the slag or scoria from the surface of
the molten metal. On the other side of the receiver, about opposite to
the slag hole, is a flue leading to the chimney, which is provided with a
damper which can be opened and closed at pleasure.
The method of working this furnace is as follows:-The cupola being
charged with pig iron, steel, or other metal, and coke or other fuel in
the usual manner, the damper in the flue is closed, the "slag bole
being rammed up also, and the tapping hole at the spout of the receiver
left open. The fire is lighted at the bottom in the ordinary way and the
blast turned on. Part of the blast (and with it the flame and heated
gases) passes through or down the perforations or inclined passages into
the lower part of the receiver and escapes by the spout. When the
bottom of the receiver has thus been thoroughly heated, and when
the metal begins to flow the tapping hole at the spout is closed, and
the slag hole and the damper in the flue leading to the chimney opened.
As the metal at or near the bottom of the cupola melts it runs through
the perforations or inclined passages into the receiver (the charge falling
down gradually in the cupola), and as the blast passes over the surface
of the molten metal in the receiver continually on its way to the
chimney or outlet it keeps it always in a molten state, thereby purifying
it and to a great extent consuming the gases.
By the use of a furnace of this description. the metal melts quicker
than in the old furnace; it is kept hotter and is consequently better
purified, and as a portion only of the blast passes up through the charge
the coke or fuel does not become consumed before it is required for
melting the charge, and hence a much smaller quantity of coke or fuel
The
than heretofore is required to melt a given amount of metal.
receiver may be made of any size, and thus a much larger quantity of
metal can be run from one furnace at a time than under the usual
process. In some cases in place of the receiver I use an air or rever-
beratory furnace into which the metal runs as it is melted, and this
furnace may be charged with large lumps of steel, or with wrought-iron
turnings or borings, or with other iron or steel which it may be desired
to mix or incorporate with the cast iron.

page_text: Such being the nature and object of my said Invention for "Improve-
ments in the Construction of Furnaces for the Manufacture of Iron and
Steel," I will now proceed to describe more in detail the manner in
which the same is to be or may be performed or carried into practical
effect, and in order that the same may be clearly understood I have
annexed hereunto a Sheet of Drawings illustrative thereof, and have
marked the same with figures and letters of reference corresponding with
those in the following explanation thereof.
Fig. 1 in the annexed Drawing is a vertical section taken longi-
tudinally through about the centre of a cupola furnace and receiver
constructed according to my Invention. Fig. 2 is a transverse section
of the receiver taken through about the line A, B, in Fig. 1; and Fig. 3
is a horizontal section or plan view of the furnace and receiver taken
through about the lines C, D, in Fig. 1.
a, a, represents an ordinary cupola furnace, the sole b, b, of which is
raised to about the level of the tuyères c, c, and sloped or inclined
towards the front, where there are perforations or inclined passages d, d,
leading from thence into the receiver c, e, which is placed at a lower
level than the sole of the furnace, and is provided at the opposite side
with a tapping hole f,f, and spout g, g, (see also front view of the same,
Fig. 4); h, h, is the "slag hole," and i, i, a passage furnished with a
damper k, k, and leading to the chimney 1, 1.
The following are some of the advantages derived from the use of a
furnace of my improved construction :―
Firstly. By having the sole or bottom of the cupola at about the level
of the tuyères a considerable quantity of coke or fuel is saved.
Secondly. By passing the flame over the surface of the molten metal
in the receiver it is consequently purified and relieved of the gases and
kept at a considerably higher temperature than under the old system.
Thirdly. As the whole of the blast does not pass through the "charge"
in the cupola or furnace the coke or fuel does not become consumed
before it is required for melting the iron or steel, and hence a much
smaller quantity of coke or fuel than heretofore is required to melt a
given quantity of metal.
Fourthly. The metal can be melted quicker and in much larger
quantities than by the old system.

page_text: Fifthly. By the flame passing through the receiver the gases emitted
by the molten metal and coke are consumed, and thus nauseous smells
are avoided.
•
And, sixthly. The quality of the metal (and consequently of the
castings) is greatly improved, as it is closer and free from " 'pellets"
and spongy or blown places.
Having now described the nature and object of my said Invention,
together with the manner in which the same is to be or may be per-
formed or carried into practical effect, I wish it to be understood that I
claim as my Invention the construction of cupola furnaces used in the
manufacture of iron and steel, substantially in the manner and for
the purposes herein-before set forth and described with reference to the
annexed Drawings, or any mere modification or imitation thereof, con-
structed and operating in substantially the same or a similar manner;
and more especially I claim, having the sole or bottom of the furnace at
or near the level of the tuyères, and causing the same to slope towards
a perforation or perforations conducting the metal into a receiver, and
passing the flame and heated gases continuously over the surface of the
molten metal in the said receiver.
In witness whereof, I, the said Josiah Swain, have hereunto set my
hand and seal, this Fourteenth day of December, in the year of
our Lord One thousand eight hundred and seventy.
Witnessed by
GEORGE DAVIES, C.E.,
Office for Patents,
Manchester.
JOSIAH SWAIN. (L.S.)