IMPROVE- MENTS IN FURNACES FOR MELTING METALS
Year: 1885

page_text: I, FRANCISCO PANADERO Y PABLOS, foreman of the foundry in the Workshops
of the Asturias, Galicia & Leon Railways Company, a resident of Leon, in the
Kingdom of Spain do hereby declare the nature of my invention for "IMPROVE-
MENTS IN FURNACES FOR MELTING METALS" and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
It is well known that a number of different kinds of furnaces exist for.melting
metals, and it is certain that the furnace which gives the most practical results
will always be preferred.
The results of the existing kinds of furnaces being well known, it is not
necessary to mention them here; but I will point out that the quantity of fuel
consumed, consumption of melting-pots, and loss of time, are excessive in comparison
with the furnace I have invented, which I call A portable furnace with inverted
flame for melting all kinds of metals in movable crucibles or melting-pots, with
hot-air injection (Panadero's system.)
In the accompanying drawings,
my furnace.
Fig. 1 is an elevation and front view of
Fig. 2 is a vertical section through A. B.
Fig. 3 is a vertical section through CD.
Fig. 4 is an upper view of the furnace.
Fig. 5 is a horizontal section through P R.
Fig. 6 is a horizontal section through E F.
Fig. 7 shows details of the additional box C.
Fig. 8 is the tongs for holding the melting pots.
My furnace is perfectly cylindrical outside, and is placed vertically on three
legs or supports, marked V in the accompanying drawing...The furnace is
composed of the cast iron pieces O, T, L, L, K, H; the upper cover PS; and the
air pipe G, placed in the lower part, containing the regulator-valve, worked by
the rod J, which ascends to the upper part... In front, in the upper shell L, is the
opening Y for cleaning and cleaning out the furnace, with its cover K; and in the
lower shell L is placed the cleaning-hole D.... At the back is the fluc, N, by which
the smoke reaches the chimney... The inside of the furnace is divided into two
parts: A is the upper portion, which is cylindrical, and of larger diameter than the
lower portion... I will call this first or upper portion the Combustion and Melting
Chamber. Here the coal is placed and the air is injected for the purpose of
melting the metal... The lower portion X, down to the bottom M, I will call the
Smoke or Draught chamber. In this latter space are placed the mouths of the.

page_text: chamber E, by which the smoke escapes and the pipes F are heated which inject
the hot air into the chamber A. At the lower part of the chamber A is the
opening Y, corresponding to the cover K.
The above described collection of parts, fitted together as shown in the drawing,
form my furnace.... The brick R is the fixed support for the crucible or melting-pot,
and 7, is the refraction or fire-proof lining.
I will now describe the use of each of the above parts.
To commence melting, every part of the furnace is opened, and the crucible or
melting pot B is placed in the brick R, a paste of powdered charcoal mixed with a
small quantity of moistened clay being first placed between the brick R and the
pot, in order to prevent the latter adhering to the brick.
The bars or pieces of metal to be melted are then placed in the pot, and the
door Y is closed, any little opening which may remain either inside or out
being covered with clay or earth. The most convenient lumps of coal are then
placed round the pot, up to the edge of same, thus filling up the space between the
pot and the chamber A. This being done, some chips shavings and pieces of
wood are placed on the edges of the pot and over its centre. These are set on fire,
and the whole remaining space of the chamber, sideways and upwards, is filled-
with coal. After an interval of ten minutes, all the parts of the furnace are closed
first sliding the drawer T M into its place, and afterwards the upper cover P S...
At the same moment the valve J is opened, thus injecting the air produced by a
ventilator.... The air enters the pipe G and passes to the pipes F, which discharge
it into the chamber A. in order to assist combustion.
The furnace being thus in a working state, it is completely closed; but as it is
necessary for the melter to know exactly what is going on inside, means are
provided by which he can do so without interfering with the work in the
least.... For this purpose he can remove the cover S to see the quantity of fuel
consumed, and the state of fusion of the metal.... He can fill up the fuel through
the opening in question; and in order to observe the state of the melting, he
inserts a cold iron rod down to the bottom of the melting-pot and.if on removing
the rod rapidly, it is found perfectly clean, this proves that the metal is at a
convenient point of fusion for the casting of pigs or other pieces ready for the
purpose.
When this moment arrives, the valve J is first closed, to cut off the current of
air.... The drawer T is immediately drawn out, and the door K and cover S are
opened at the same time... The box C is then placed on the two knobs or supports
at the opening Y, and by means of a simple rod inserted through the hole in the
centre of the cover P, all the coal contained in the chamber A is made to fall down
the inclined plane of the door Y into the box C, in which the coal is kept alight,
to be ready for the next melting.... This box is then removed from the furnace,
and after sliding the cover P over the plate H, the furnace is open, ready for
removing the melting-pot B by means of the tongs U.... To prepare for another
melting, before placing the pot in the furnace the metal to be melted is put
into the pot, the opening Y is closed, and the melting pot is placed on the
brick support R, a few pieces of coal being arranged so that the pot stands
perfectly level... The box C, containing coal still alight from the last melting, as
shown in the drawing, is instantly placed over the edges of the furnace, and the
bolt fitted in the bottom of the box being pulled, the weight of the coal causes the
hinged bottom to open, and the contents fall into the chamber A... The cover P S
is immediately closed, the drawer T M is pushed in, the air is injected, and the
work of the furnace recommences.
Although from the simple shape and arrangement of the furnace, an approximate
idea can be formed of the phenomena taking place inside during the melting,
I think it advisable to give some details, as clearly as possible.
At the place where combustion and melting otake place, after having made use
of the greater portion of the highest temperatures acting directly upon the mass
of metal, the flame descends to the lower portion, enwrapping and enclosing the

page_text: melting-pot, in consequence of its conical form, and thus keeping the metal in a
proper fluid state.
The remainder of the heat is also made use of, for it passes through the smoke-
chamber X into the chamber E, which surrounds the pipes F, and the latter being
thus heated, increase the temperature of the air that passes through them to reach
the chamber A. It will be noticed that in my system nearly the whole of the
heat produced by the fuel consumed is made use of; which produces a saving
in fuel... Also, the melting pots used last longer than is the case with other
systems, because the portion of the pot which has the fiercest heat to bear being
the upper part, the usual breakages at the bottom and consequent loss of metal
are thus avoided, which are so common in other systems.... For the same reason,
the pots used will last three times the usual number of meltings, until worn down
to the bottom; that is to say, the melting-pots employed in my system are worn
out by gradual wearing away at the edges, but never through breakages anywhere.
One of the objections to all furnaces in practice is the cleaning out of the
cinders, which generally requires the work to be stopped for that purpose, and
even when the clearing-out is done under the most favourable conditions, it is well
known that a time comes when it is necessary to stop the work altogether for this
purpose....In my furnace the contrary takes place The more the furnace is used,
the easier the automatic clearing-out becomes, without requiring the melter to
occupy himself with this operation, nor stop the regular work of the furnace in the
least, as the cinders are automatically expelled by means of the combustion itself,
and fall to the bottom M, together with any small portions of metal which may
have run over the edge of the melting-pot, and can be instantly removed by
merely pulling out the drawer T, which discharges then outside, where any pieces
that can still be used can be picked out; an advantage not found in any of the
existing systems.
In conclusion, I will state that my furnace is more economical in repairs than
any other, as when it becomes worn inside it is only necessary to renew the
refractory or fire-proof shell or lining of the chamber A. where the combustion
takes place, and it is not necessary to take to pieces the whole of the inside of the
furnace as in other systems.
Having now particularly described & ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
First. This new system of portable furnace with inverted flame, for melting all
classes of metals in movable melting-pots, with hot air injection; substantially as
described above and represented in the accompanying drawings.
Second. The application of an inverted flame for the purpose of melting all
kinds of metals in this class of furnaces, by which means the melting of the metal
is more rapidly accomplished, and breakages in the melting-pots are avoided ;
substantially as described.
Third. The conical shape of the interior of the furnace, which produces a saving
of 50 per cent in fuel, and compels the flame to descend, enwrapping and enclosing
the whole of the melting-pot; substantially as described and represented.
Fourth. The application of a simple brick (letter R in drawing) as a support for
the melting-pot; thus doing away with all the expensive grates and supports
hitherto employed in these kinds of furnaces; substantially as described and
represented.
Fifth. The arrangement of the two openings (letter E in drawing) placed in the
chamber X; by which all the smoke and gases produced by the combustion and
melting (which produce such evil effects on the workmen) are carried downwards;
substantially as described and represented.
Sixth. The movable bottom inside the furnace, made in the form of a sliding
drawer (letters M T in drawing), into which fall automatically all the cinders
and any portions of metal which may escape from the melting pot, which can be

page_text: instantly removed outside, without stopping the work of the furnace in the least;
substantially as described."
Seventh. The automatic system described, by which the furnace clears itself of
cinders and these can be examined outside without stopping the work of melting
in the least; substantially as described.
>>>>
Eighth. The application and arrangement of hot air from above in this class of
furnaces, the air being injected by means of three special openings placed in the
combustion and melting chamber; substantially as described.
Ninth. The aperture, with its cover (letter S in drawing), situated in the upper
cover of the furnace through which the state of the metal can be observed during
the melting, and additional fuel can be put on without stopping the work of the
furnace in the least for either of these operations; substantially as described and
represented.
Tenth. The shape and arrangement of the opening with inclined plane and
hinged door, letters Y and K in drawing, in the upper part of the furnace in front,
communicating with the combustion and melting chamber; through which the
fuel is removed before taking out the pot containing the melted metal; substantially
as described and represented.
Eleventh. The aperture and cover D, situated in the lower front of the furnace;
by which the opening of the smoke-chamber are cleaned; substantially as described
and represented.
Twelfth. The shape and arrangement of the heating-chamber E, through which
the smoke escapes; substantially as described and represented.
Thirteenth. The shape and arrangement of the air-chamber and injecting pipes
(letter F) substantially as described and represented.
Fourteenth. The shape and arrangement of the air-pipe G, placed in the lower
part of the furnace outside substantially as described.
Fifteenth. The arrangement of the flue for conducting the smoke to the chimney
(letter N in drawing) substantially as described and represented.
Sixteenth. The shape of the legs supporting the whole furnace (shown at
letter V), substantially as described and represented.
Seventeenth. The shape and arrangement of all the parts composing the
refractory or fire proof shell or lining inside the furnace (letter Z in drawing)
substantially as described and represented.
Eighteenth. The shape and arrangement of all the parts composing the outside
of the furnace (shown at letters L, L, H, 0); substantially as described and
represented.
Nineteenth. The arrangement of the combustion and melting chamber A inside
the upper part of the furnace; substantially as described and represented.
Twentieth. The shape and arrangement of the spare or additional box C for
keeping the fuel alight and removing from and replacing said fuel into the
furnace; substantially as described and represented.
Twenty-first. The tongs (letter U in drawing) for placing and removing the
melting pots from the furnace; substantially as described and represented.
Dated this 9th day of August 1885.