IMPROVE- MENTS IN THE CONSTRUCTION OF FURNACES FOR HEATING, PUDDLING, OR MELTING IRON, STEEL, OR OTHER METALS
Year: 1872

page_text: LETTERS PATENT to Robert Edwards and Thomas Robinson, both of
Sheffield, in the County of York, for the Invention of "IMPROVE-
MENTS IN THE CONSTRUCTION OF FURNACES FOR HEATING, PUDDLING, OR
MELTING IRON, STEEL, OR OTHER METALS."
Scaled the 2nd August 1872, and dated the 15th February 1872.
PROVISIONAL SPECIFICATION left by the said Robert Edwards and
Thomas Robinson at the Office of the Commissioners of Patents,
with their Petition, on the 15th February 1872.
We, ROBERT EDWARDS and THOMAS ROBINSON, both of Sheffield, in
the County of York, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES FOR HEATING, PUDDLING,
OR MELTING IRON, STEEL, OR OTHER METALS," to be as follows:-
The improved furnace consists of two heating portions, each portion
having a grate and firing opening or door, and the usual door or doors
for the purpose of charging and discharging. The flame, heat, and

page_text: smoke pass from each end over suitable bridges varying as in ordinary
furnaces according to the materials in the course of being heated, and
meet in the central flue, Between each part of the double furnace we
have a cast-iron girder with supporting brackets for carrying the roof at
the junction of the furnace and flue.
This flue is the special feature of our improved furnace, and can be
taken either upwards or downwards, or otherwise, as may be required
or convenient, and either way the flame and consumed smoke may be
utilized by letting it pass through the flue or flues of steam boilers. The
flame and unburnt gases given off from each fire in passing into the
central flue meet each other, and each fire on coming in contact with
the other causes a perfect and complete combustion of all the smoke
and gases of the opposite fire. With four of these furnaces as much
work can be done as with nine or ten ordinary furnaces, and each double
furnace occupies but slightly more space than an ordinary furnace, and
there is therefore much space saved, which is an important consideration.
There is in this furnace a regular and constant heat; and an enormous
advantage is that the double furnace can be charged and discharged at
the same time without the necessity for the furnace becoming com-
paratively cold for an hour or more, as is the case in the present kind of
furnace.
Owing to the perfect combustion and the fact that one furnace door
may be opened for charging without deteriorating the quality of the
heat passing into the flue, the heat on being allowed to pass through a
boiler is uniform and constant, and therefore the boiler flue plates are
not subject to the same sudden expansion and contraction and wear and
tear of material, and consequent danger of explosion, as must be the
case with the ordinary furnace boiler, because during the charging of
the furnace the heat is not nearly so great as when the door is closed,
and the pressure of steam cannot therefore be regular or depended
upon.
This furnace can easily be adapted for melting steel, brass, and other
metals in pots, or as an air furnace, which could be tapped at alternate
ends, and therefore secure an almost continuous supply of molten
metal.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Edwards and Thomas Robinson in the
Great Seal Patent Office on the 15th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
EDWARDS and THOMAS ROBINSON, both of Sheffield, in the County of
York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of February, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Robert Edwards and Thomas Robinson,
Her special license that we, the said Robert Edwards and Thomas
Robinson, our executors, administrators, and assigns, or such others as
we, the said Robert Edwards and Thomas Robinson, our 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 THE
CONSTRUCTION OF FURNACES FOR HEATING, PUDDLING, OR MELTING IRON, STEEL, OR
OTHER METALS," upon the condition (amongst others) that we, the said
Robert Edwards and Thomas Robinson, our executors or administrators,
by an instrument in writing under our, or one of our, 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 Robert Edwards, on behalf of
myself and the said Thomas Robinson, 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) :-
This improved furnace consists of two heating portions, each portion
having a grate and firing opening or door and the usual door or doors
for the purpose of charging and discharging. The flame, heat, and
smoke pass from each end over suitable bridges varying as in ordinary
furnaces according to the materials in the course of being heated and

page_text: meet in a central flue. Between each part of the double furnace we
have a cast-iron girder with supporting brackets for carrying the roof at
the junction of the furnace and flue.
'This flue is the special feature of our improved furnace, and can be
taken either upwards or downwards or otherwise as may be required or
convenient, and either way the flame and consumed smoke may be utilized
by letting it pass through the flue or flues of steam boilers. The flames
and unburnt gases given off from each fire in passing into the central flue
meet each other, and each fire on coming in contact with the other causes
a perfect and complete combustion of all the smoke and gases of the
opposite fire.
With four of these furnaces as much work can be done as
with nine or ten ordinary furnaces, and each double furnace occupies but
slightly more space than an ordinary furnace, and there is therefore
much space saved which is an important consideration. There is in this
furnace a regular and constant heat; and an enormous advantage is that
the double furnace can be charged and discharged at the same time
without the necessity for the furnace becoming comparatively cold for
an hour or more as is the case in the present kind of furnace.
Owing to the perfect combustion and the fact that one furnace door
may be opened for charging without deteriorating the quality of the
heat passing into the flue, the heat on being allowed to pass through a
boiler is uniform and constant, and therefore the boiler flue plates are
not subject to the same sudden expansion and contraction, and wear and
tear of material and consequent danger of explosion as must be the
case with the ordinary furnace boiler, because during the charging of the
furnace the heat is not nearly so great as when the door is closed, and
the pressure of steam cannot therefore be regular or depended upon.
This furnace can easily be adapted for melting steel, brass, and other
metals in pots, or as an air furnace which could be tapped at alternate
ends and therefore secure an almost continuous supply of molten
metal.
Such being the nature and object of our said Invention for " Improve-
ments in the Construction of Furnaces for Heating, Puddling, or Melt-
ing Iron, Steel, or other Metals," I will now proceed to describe more in
detail the manner in which 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 :-

page_text: Fig. 1 in the annexed Drawing is a longitudinal section, Fig. 2 an
end elevation, and Fig. 3 a horizontal section or ground plan of a
double grate furnace constructed according to our Invention; the
central flue being carried upwards and the flame and heated gases
utilized for heating a vertical flued steam boiler.
Figs. 4 and 5 are longitudinal and horizontal sections of a similar
double grate furnace wherein the central flue is carried downwards.
a, a, are the walls of the furnace; b, b, the fire-grates; and c, c, the
bridges; d, d, is the hearth or bed of the furnace (which in Figs. 4 and 5
is divided into two in order to allow the flue to pass downwards), and
e, e, is the arched roof, the centre part of which at the junction of the
furnace and flue may be carried by a cast-iron girder with supporting
brackets; ff, is the central flue which may be carried either upwards
as shown at Figs. 1, 2, and 3, or downwards as seen at Figs. 4 and 5,
or otherwise as may be found most convenient, and which in order to
utilize the waste heat may be connected to the flues g, g, of a vertical
or other boiler h, h, as shown, or it may be conveyed away and utilized
or otherwise as may be thought desirable; i, i, are the doors or firing
openings for supplying the furnace with fuel, and k, k, are the openings
for introducing, working, and discharging the metal.
Having now described the nature and object of our said Invention for
"Improvements in the Construction of Furnaces for Heating, Puddling,
or Melting Iron, Steel, or other Metals," together with the manner in
which the same is to be or may be performed or carried into practical
effect, I wish it to be understood that we claim as our Invention, the
construction of such furnaces with two grates (each having its own
door or opening), the flame and heated gases from which pass over
bridges to the hearth or bed of the furnace and meet in one central flue
passing upwards, downwards, or otherwise, substantially as herein-before
described and illustrated by the accompanying Drawings.
In witness whereof, I, the said Robert Edwards, on behalf of my-
self and the said Thomas Robinson, have hereunto set my hand
and seal, this Thirteenth day of August, in the year of our Lord
One thousand eight hundred and seventy-two.
ROBERT EDWARDS. (L.S.)