IMPROVEMENTS IN CUPOLA FURNACES
Year: 1873

page_text: LETTERS PATENT to Eugène Voisin, of Bourges, France, but tem-
porarily of No. 4, South Street, Finsbury, in the County of
Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS IN
CUPOLA FURNACES."
Sealed the 19th December 1873, and dated the 7th October 1873.
PROVISIONAL SPECIFICATION left by the said Eugène Voisin at the
Office of the Commissioners of Patents, with his Petition, on the
7th October 1873.
I, EUGÈNE VOISIN, of Bourges, France, but temporarily of No. 4, South
5 Street, Finsbury, in the County of Middlesex, Civil Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN CUPOLA
FURNACES," to be as follows, that is to say :-
The object of these improvements is,―
Firstly. To effect the regeneration and combustion in the interior of
the furnace itself, of the gases which in the ordinary construction of
Ja funnnce are burnt of the throat thomof though

page_text: the melting power of the furnace, keeping the throat of the furnace
comparatively cool and economizing fuel.
Secondly. To enable a much larger quantity of molten metal than
hitherto to be collected from a furnace at a time, thereby effecting a
great economy of time and labor where large castings have to be made.
To carry out the first part of my Invention I employ a second set of
tuyeres placed above the ordinary tuyeres, such two rows of tuyeres
being parallel and working together, the distance between them varying.
The air is supplied to both sets of tuyeres from an annular distributing
chamber formed on the outside, or within the iron casing of the furnace,
and communicating with the fan or blast engine. The upper set of
tuyeres are of a smaller size than the lower set, and of sufficient size to
effect the regeneration and combustion of the gases in the centre of the
furnace. This improvement is applicable to blast cupola furnaces.
The second part of this Invention consists in the application to cupola
furnaces of a chamber or receiver in communication with the crucible or
hearth of the furnace. This receiver serves to collect the molten metal,
thereby enabling a larger quantity of metal than hitherto to be run off
at one time, so as to allow of large castings being made from a com-
paratively small furnace. This latter improvement is applicable to
existing cupola furnaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Eugène Voisin in the Great Seal Patent Office on
the 7th April 1874.
TO ALL TO WHOM THESE PRÉSENTS SHALL COME, I, ÉUGÈNE 2
VOISIN, of Bourges, France, but temporarily of No. 4, South Street,
Finsbury, in the County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of October, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty- 3
seventh year of Her reign, did, for Herself, Her heirs and successors,
givo and grant unto me, the said Eugène Voisin, Her special licence
that I, the said Eugène Voisin, my executors, administrators, and

page_text: assigns, or such others as I, the said Eugène Voisin, my exccutors,
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
CUPOLA FURNACES," upon the condition (amongst others) that I, the said
Eugène Voisin, 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 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 Eugène Voisin, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereto annexed,
and to the figures and letters marked thereon, that is to say:-
The object of these improvements is,―
Firstly. To effect the combustion in the interior of the furnace itself,
of the gases which in the ordinary construction of cupola furnace are.
burnt at the throat or top thereof, and by which improvements I
cconomise fuel, greatly increase the melting power of the furnace, and
keep the throat of the furnace comparatively cool.
Secondly. To enable a much larger quantity of molten metal than
hitherto to be collected from a furnace at one time, thereby effecting an
economy of time and labor where large castings have to be made.
To carry out the first part of my Invention, I so place above the
ordinary row of tuyeres (which act on and utilise the coke to the full
extent in the ordinary manner) a second set or or row of tuycres of such
dimensions as shall serve to supply to the gases produced by the first or
ordinary row of tuyeres only the quantity of air necessary for effecting
their combustion (without burning any coke) in the interior, instead of
at the throat of the furnace as hitherto. This second set of tuyeres is
so placed that the gases which have become regenerated by passing over
the hot coke between the two rows of tuyeres are consumed while they
are in contact with the metal, thus producing a second zone of fusion,.

page_text: thereby considerably reducing the consumption of coke, and accelerating
the melting power of the furnace. The gases being consumed in the
interior of the furnace no flame is produced at the throat of the furnace,
which is comparatively cool.
The number of tuyeres varies according to the size of the cupola, and
is the same for each row.
The two rows or sets of tuyeres are worked together, the air being
supplied thereto from an annular distributing chamber formed on the
outside, or within the iron casing of the furnace, and communicating
with the fan or blast engine.
The second part of this Invention consists in the application to or
placing at the back of cupola furnaces of a chamber or receiver in
communication with the crucible or hearth of the furnace in such a way
as to cause the molten metal to retain its heat while it is being collected,
thereby enabling a larger quantity of metal than hitherto to be run off
at one time, and so allow of large castings being made from a com-
paratively small furnace.
Having thus described the nature of my said Invention, I will now
proceed to more particularly describe the same, and the means for
carrying it into effect by reference to the accompanying Drawing, in
which Figure 1 is a front elevation of a cupola furnace with the first
part of my improvements applied thereto; Figure 2 is a vertical section
of same; Figure 3 is a horizontal section on line a, b, of Figure 1; and
Figure 4 a horizontal section on line c, d, Figure 2.
Figure 5 is a front elevation of a cupola furnace, shewing all my
improvements applied thereto; Figure 6, a vertical section of same;
Figure 7, horizontal section on line a, b, Figure 5; and Figure 8,
horizontal section on line c, d, Figure 6.
"
Similar letters in all the Figures represent similar parts.
· A, A, is the annular distributing chamber for supplying air to the
tuyeres. In the Drawing this chamber is shewn placed outside the
furnace, but it may also be placed within the iron casing, as herein-
before described. B is a pipe for conveying the blast into the chamber A;
T, T, the first or ordinary row of tuyeres for burning the coke producing
the gases and forming the first zone of fusion; t, t, second row of

page_text: tuyeres of a smaller size than the first row, and serving to consume the
gases immediately after their regeneration, and producing the second
zone of fusion.
I place the two rows of tuyeres at a distance from each other of from
one foot eight inches for small cupolas; as shewn in the Drawing, to two
feet four inches for large cupola furnaces...
I make the area of the section of the second or upper row of tuyeres
one-half that of the lower or first row of tuyeres.
S, S, cast-iron sight hole frames with colored glass, to allow of
examining the progress of the fusion. These sight holes are placed
opposite the tuyeres; P is the ordinary door for drawing off the molten
metal from the crucible; G; cast-iron lining to protect the brickwork at
the throat of the furnace from the effects of the concussion of the pieces
of metal thrown into the furnace.
In Figures 5 to 8 R is the chamber or receiver placed at the back of
the cupola, and communicating with the crucible or hearth C by means
of the opening O in the lower part of the sole plate, thus allowing the
molten metal to run from the crucible into the receiver. When the
receiver contains a sufficient quantity of metal for the required casting
the furnace is tapped, and the liquid metal passes from the receiver
through the opening O, and through the hot furnace out by the door P.
When the receiver is not required the opening O is stopped up, and the
cupola may then be used as if it had no receiver.
The improvements herein-before described are applicable to ordinary
cupolas.
Having now described my said Invention, and the best means I am
acquainted with for carrying the same into effect, I would have it
understood that I lay no claim to the employment of a second row
of tuyeres, or of the annular chamber, nor to the receiver herein-before
described, as the same have before been employed in connection with
cupola furnaces for other purposes, or in a different manner; but what I
claim is-
Firstly. The employment of a second set or row of tuyeres so placed
and of such dimensions as to create a second zone of fusion by consuming
the gases in the interior of the furnace which have been hitherto
consumed at the throat thereof, as herein-before described.

page_text: Secondly. The placing a receiver at the back of the cupola furnace, in
communication with the crucible or hearth in such a way as to cause the
metal to pass back through the heated hearth of the furnace, as and for.
the purpose herein-before described.
In witness whereof, I, the said Eugène Voisin, have hereto set my a
hand and seal, this First day of April, in the year of our Lord
One thousand eight hundred and seventy-four.
E. VOISIN. (L.S.)